To see the other types of publications on this topic, follow the link: System failures (Engineering) Risk assessment. System design.
Journal articles on the topic 'System failures (Engineering) Risk assessment. System design'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'System failures (Engineering) Risk assessment. System design.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Ratnayake, R. M. Chandima. "Knowledge based engineering approach for subsea pipeline systems’ FFR assessment." TQM Journal 28, no. 1 (January 11, 2016): 40–61. http://dx.doi.org/10.1108/tqm-12-2013-0148.
Full textAbstract:
Purpose – The purpose of this paper is to focus on developing a knowledge-based engineering (KBE) approach to recycle the knowledge accrued in an industrial organization for the mitigation of unwanted events due to human error. The recycling of the accrued knowledge is vital in mitigating the variance present at different levels of engineering applications, evaluations and assessments in assuring systems’ safety. The approach is illustrated in relation to subsea systems’ functional failure risk (FFR) analysis. Design/methodology/approach – A fuzzy expert system (FES)-based approach has been proposed to facilitate FFR assessment and to make knowledge recycling possible via a rule base and membership functions (MFs). The MFs have been developed based on the experts’ knowledge, data, information, and on their insights into the selected subsea system. The rule base has been developed to fulfill requirements and guidelines specified in DNV standard DNV-RP-F116 and NORSOK standard Z-008. Findings – It is possible to use the FES-based KBE approach to make FFR assessments of the equipment installed in a subsea system, focussing on potential functional failures and related consequences. It is possible to integrate the aforementioned approach in an engineering service provider’s existing structured information management system or in the computerized maintenance management system (CMMS) available in an asset owner’s industrial organization. Research limitations/implications – The FES-based KBE approach provides a consistent way to incorporate actual circumstances at the boundary of the input ranges or at the levels of linguistic data and risk categories. It minimizes the variations present in the assessments. Originality/value – The FES-based KBE approach has been demonstrated in relation to the requirements and guidelines specified in DNV standard DNV-RP-F116 and NORSOK standard Z-008. The suggested KBE-based FES that has been utilized for FFR assessment allows the relevant quantitative and qualitative data (or information) related to equipment installed in subsea systems to be employed in a coherent manner with less variability, while improving the quality of inspection and maintenance recommendations.
2
Елисеева, Татьяна, and Tatyana Eliseeva. "INFLUENCE OF USE COMPLETENESS OF ENGINEERING SYSTEM MODEL UPON ACCURACY AND ADEQUACY OF RELIABILITY ASSESSMENT." Bulletin of Bryansk state technical university 2016, no. 3 (September 30, 2016): 210–15. http://dx.doi.org/10.12737/22169.
Full textAbstract:
An overall purpose of researches – improvement of assessment methods of engineering systems reliability at the stage of design.
To achieve the end specified within the bounds of the investigation there was established that one of the most significant factors defining the effectiveness of the reliability assessment at the stage of designing is the completeness of a model used. For the assessment of model completeness by the example of a failure tree it was offered to determine a correlation between levels of a logical model of reliability and kinds of engineering consistency regulated by RSS 30709-2002 “Engineering Consistency. Terms and Definitions”. Within the bounds of the paper there is analyzed a minimum set of the sorts engineering consistency (dimensional consistency of system elements, compatibility of ele-ments according to reliability, interoperability) the account of which requires various degrees of detailed elaboration of a model and supposes the existence of corresponding source data including those established at the identification of logic connections between failures and the analysis of possible failures caused by a common reason.
For the systematization of research results there is developed a matrix of correlation of analyzed kinds of engineering consistency with the levels of a failure tree and the values of the assessment of a quadratic means of deviation (QMD) of expected results. The mathematical dependences allowing the definition of QMD values at every level of the logic model of relia-bility are developed. To account for the progressive-ness of a QMD value at the decrease of assessment reliability by analogy with Taguchi function of losses it is offered to use a parabolic dependence. The approach offered is particularly urgent for methods where the accuracy of results obtained determines the degree of a risk of manufacturers caused by wrong or untimely management or technical decision-makings. The trend of risk changes for manufacturers depending on QMD of a resultant value allows explaining diagrams presented in the paper.
The results obtained explain the dependence of accuracy and reliability of a reliability assessment on the completeness of use of the model and show a trend of the influence of parameters pointed out upon risk probability of manufacturers at the decisionmaking at the stage of designing.
3
Li, J.-P., and G. Thompson. "Mechanical failure analysis in a virtual reality environment." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 219, no. 3 (August 1, 2005): 237–50. http://dx.doi.org/10.1243/095440805x28258.
Full textAbstract:
This paper is part of a research theme to develop methods that enhance risk assessment studies by the use of ‘automated’ failure analysis. The paper presents an approach to mechanical failure analysis and introduces a mechanical failure analysis module that can be used in a virtual reality (VR) environment. The module is used to analyse and predict failures in mechanical assemblies; it considers stress related failures within components, as well as failures due to component interactions. Mechanical failures are divided into two categories in this paper: material failures and interference failures. The former occur in components and the latter happen at the interface between components. Individual component failures can be analysed readily; a contribution of the mechanical failure analysis module is to predict interference failures. A mechanical failure analysis system that analyses and visualizes mechanical failures in a virtual environment has been developed. Two case studies demonstrate how the system carries out failure analysis and visualization as design parameters are changed.
4
Chou, I.-Chi, Hsu-Chin Hsueh, and Ren-Guey Lee. "EXAMPLE FOR MOBILE ECG HOLTER DESIGN USING FMEA MODEL." Biomedical Engineering: Applications, Basis and Communications 21, no. 01 (February 2009): 61–70. http://dx.doi.org/10.4015/s101623720900109x.
Full textAbstract:
This paper describes an approach for evaluating the risk of components used in the Holter. Holter is a portable device for recording patients' electrocardiogram in medicine. Holter might hurt users as a result of a bad design, and might record incorrectly when malfunction happens. To prevent risk of injury, we analyze the potential failures of the Holter based on the Failure Mode and Effects Analysis, which is a risk assessment technique. Then, we calculate the Risk Priority Number (RPN) of each failure. According to the RPN, we give two strategies for reducing the risk. One is protection, and the other is alarm. The protection system is used to prevent hazards of the Holter from incorrect operations by the user, and the alarm system is used to detect the malfunction of the Holter. The experimental results show that the safety of the Holter is improved with these two circuits.
5
Bakhat, Rim, and Mohammed Rajaa. "Risk Assessment of a Wind Turbine Using an AHP-MABAC Approach with Grey System Theory: A Case Study of Morocco." Mathematical Problems in Engineering 2020 (August 13, 2020): 1–22. http://dx.doi.org/10.1155/2020/2496914.
Full textAbstract:
Clean energy has become a growing concern, and many organizations pay attention to environmental protection and energy production as well. In the last few decades, the wind turbine has become the core of clean energy production and has advanced in generating electricity from 40 kW to 5 mW. However, the new design of the wind turbine causes several potential failures which frequently lead to the inability to accomplish the operational requirements intended to meet the customers’ expectations. As a solution to this problem, the present paper proposes a novel systematic approach that combines Multicriteria Decision-Making (MCDM) techniques and Failure Mode Effects and Criticality Analysis (FMECA) tool to reveal the fatal failures and optimize the maintenance actions. To further develop the preceding framework, this work will not only rely on the three risk factors that are involved in the traditional Risk Priority Numbers (RPN) approach but also will consider the economic aspect of the system. In the proposed approach, the grey Analytic Hierarchy Process (AHP) method is applied in the first place to calculate the weights of the four risk factors criteria. Second, the grey Multiattribute Border Approximation area Comparison (MABAC) technique is applied to rank the failure modes and their criticality on the whole system. The proposed model is verified within an organization of renewable energy production in Morocco. Furthermore, the results of the comparative and the sensitivity analysis affirm that the proposed research framework is adequate for enhancing other complex systems design, especially in a developing world where funds and resources are scarce.
6
Carro, Andrés, Ricardo Chacartegui, Carlos Tejada, Georgios Gravanis, Muhammad Eusha, Voutetakis Spyridon, Papadopoulou Simira, and Carlos Ortiz. "FMEA and Risks Assessment for Thermochemical Energy Storage Systems Based on Carbonates." Energies 14, no. 19 (September 22, 2021): 6013. http://dx.doi.org/10.3390/en14196013.
Full textAbstract:
Thermochemical energy storage systems from carbonates, mainly those based on calcium carbonate, have been gaining momentum in the last few years. However, despite the considerable interest in the process, the Technology Readiness Level (TRL) is still low. Therefore, facing the progressive development of the technology at different scales is essential to carry out a comprehensive risk assessment and a Failure Mode Effect and Analysis (FMEA) process to guarantee the safety and operation of the technology systems. In this study, the methodology was applied to a first-of-its-kind prototype, and it is a valuable tool for assessing safe design and operation and potential scaling up. The present work describes the methodology for carrying out these analyses to construct a kW-scale prototype of an energy storage system based on calcium carbonate. The main potential risks occur during the testing and operation stages (>50% of identified risks), being derived mainly from potential overheating in the reactors, failures in the control of the solar shape at the receiver, and potential failures of the control system. Through the assessment of Risk Priority Numbers (RPNs), it was identified that the issues requiring more attention are related to hot fluid path to avoid loss of heat transfer and potential damages (personal and on the facilities), mainly due to their probability to occur (>8 on a scale of 10). The results derived from the FMEA analysis show the need for specific control measures in reactors, especially in the calciner, with high operation temperatures (1000 °C) and potential effects of overheating and corrosion.
7
Bhkukya, ShankarNayak, and Dr Suresh Pabboju. "A Framework for Enhanced Tropos Goal-Driven Risk Assessment in Requirements Engineering." International Journal of Engineering & Technology 7, no. 2.23 (April 20, 2018): 510. http://dx.doi.org/10.14419/ijet.v7i2.23.15345.
Full textAbstract:
Every process model used by software industry has different phases including requirement engineering. This is the crucial phase as it is preceded by other phases and provides valuable inputs to the design phase. Risk assessment made in this phase can help avoid wastage of time, effort, cost and budget overruns and even missed delivery deadlines. Traditionally risks are analyzed in terms of technical aspects like failures in the working system, unavailability of certain services, and fault intolerances to mention few. The identified risks are used to have countermeasures. However, it causes the life cycle of the system to be repeated right from the requirements engineering. On the contrary, risk analysis in the requirements engineering phase can prove fact that a stitch in time saves nine. Therefore early detection of risks in the system can help improve efficiency of software development process. Goal-oriented risk assessment has thus gained popularity as it is done in the requirements analysis phase. Stakeholder interests are considered to analyze risks and provide countermeasures to leverage quality of the system being developed. In this paper, a formal framework pertaining to Tropos goal modelling is enhanced with quantitative reasoning technique coupled with qualitative ones. Towards this end we used a conceptual framework with three layer such as asset layer, event layer and treatment layer. We used a case study project named Loan Origination Process (LOP) to evaluate the proposed framework. Our framework supports probability of satisfaction (SAT) and denial (DEN) values in addition to supporting qualitative values. The Goal-Reasoning tool is extended to have the proposed quantitative solution for risk analysis in requirements engineering. The tool performs risk analysis and produces different alternative solutions with weights that enable software engineers or domain experts to choose best solution in terms of cost and risk. The results revealed the performance improvement and utility when compared with an existing goal-driven risk assessment approach.
8
Pokhabov, Yu P. "What should mean dependability calculation of unique highly vital systems with regards to single-use mechanisms of spacecraft." Dependability 18, no. 4 (December 5, 2018): 28–35. http://dx.doi.org/10.21683/17292646-2018-18-4-28-35.
Full textAbstract:
Aim. Calculations are an integral part of the development of any complex technical object. Normally, they are subdivided into the calculations to confirm product operability (kinematic, electrical, thermal, strength, hydraulic and pneumatic systems analysis, etc.) and calculations to confirm its dependability (calculation of reliability, longevity, maintainability, storability and other indicators). As it is understood and provided in statutory documents, dependability calculation involves procedures of identification of an object’s dependability indicators using methods based on their calculation using reference information on the object’s components dependability, on the dependability of analog objects, on the properties of the materials and other information available at the time of calculation. However, in the case of development of unique highly vital systems, obtaining statistical data for dependability calculation is impossible due to two conflicting conditions, i.e. the limited number of produced objects and the requirement of high accuracy of the input information. Nevertheless, in the author’s opinion dependability calculations must be performed. The only question is how to calculate the dependability and what such calculation should mean.Methods. In the classic dependability theory, the conventional understanding of probability of no-failure is the frequency of failures in time, yet for unique highly vital systems the failure rate must tend to zero over the entire period of operation (preferably, there should be no failures at all). For this reason the concept of “failure” in the context of unique highly vital systems should probably be interpreted not as an event, i.e. any fact, which as a result of experience can occur or not occur, but as possible risk, i.e. an undesirable situation or circumstance that is characterized by the probability of occurrence and potentially negative consequences. Then, an event in the form of a real or potential failure in operation can be associated with a risk in the form of probability of failure with negative consequences, which in terms of the consequences is equally unacceptable with regard to unique highly vital systems. In this case dependability calculation can be reasonably substituted with risk assessment, a process that encompasses risk identification, risk analysis and comparative risk assessment. Thus, risk assessment enables the achievement of the target dependability directly by substantiating the stability of manifestation of a specific product’s properties and not indirectly through undependability caused by failures of analog products.Results. The paper shows the procedure of risk assessment for unique highly vital systems. Using the example of a mechanical system with actuated parts represented by a spacecraft single-section pivoted rod the risk assessment procedures are shown. The feasibility of risk assessment with the use of design engineering analysis of dependability is demonstrated.Conclusions. It is shown that the absence of statistical data on the dependability of analogs of unique highly vital systems does not prevent dependability calculation in the form of risk assessment. Moreover, the results of such calculations can be a source and guidelines for adopting design and process engineering solutions in the development of products with target dependability indicators. However, legalizing the method of such calculations requires the modifications of the technical rules and regulations to allow for dependability calculation by other means than with the use of statistical data on the failures of analogs.
9
LUNDTEIGEN, MARY ANN, and MARVIN RAUSAND. "RELIABILITY ASSESSMENT OF SAFETY INSTRUMENTED SYSTEMS IN THE OIL AND GAS INDUSTRY: A PRACTICAL APPROACH AND A CASE STUDY." International Journal of Reliability, Quality and Safety Engineering 16, no. 02 (April 2009): 187–212. http://dx.doi.org/10.1142/s0218539309003356.
Full textAbstract:
This article presents a practical approach to reliability assessment of a complex safety instrumented system that is susceptible to common cause failures. The approach is based on fault tree analysis where the common cause failures are included by post-processing the minimal cut sets. The approach is illustrated by a case study of a safety instrumented function of a workover control system that is used during maintenance interventions into subsea oil and gas wells. The case study shows that the approach is well suited for identifying potential failures in complex systems and for including design engineers in the verification of the reliability analyses. Unlike many software tools for fault tree analysis, the approach gives conservative estimates for reliability. The suggested approach represents a useful extension to current reliability analysis methods.
10
Qu, Na, Zhong Hai Li, Nai Wei Cheng, and Jian Wei Li. "Failure Risk Evaluation of Security System Based on Fuzzy FTA." Advanced Materials Research 945-949 (June 2014): 1094–97. http://dx.doi.org/10.4028/www.scientific.net/amr.945-949.1094.
Full textAbstract:
The reliability of security system affects the ability of the system to protect people's lives and property safety. Failure risk assessment of security system is an effective method to test the reliability of the system. The fault tree analysis method has been applied to analyze the system failure risk from the angle of each part and considering the human factors. The traditional fault tree analysis method assumes that the probability of bottom events is certain to calculate the top event probability. To obtain accurate bottom events probability is difficult, even impossible because statistical data is not sufficient and the bottom events is fuzzy in fact. Analysis of the fuzzy mathematics theory is introduced into the fault tree. The calculation provides reference for the system design and management.
11
SON, YOUNG KAP, and GORDON J. SAVAGE. "QUALITY AND PERFORMANCE RELIABILITY ASSESSMENT OF MULTI-RESPONSE DEGRADING SYSTEMS." International Journal of Reliability, Quality and Safety Engineering 13, no. 04 (August 2006): 289–309. http://dx.doi.org/10.1142/s0218539306002264.
Full textAbstract:
This paper presents a non-sampling based method for the simultaneous evaluation of quality and performance reliability of engineering systems with multiple time-variant responses due to multiple degrading components. This work provides a platform for robust design of degrading systems. The system performance degradations are related to component degradations using mechanistic models. The system soft failure is defined as the non-conformance of any response with respect to critical levels and such relations are easily modeled as time dependent limit-state functions. Then, for discrete time it is shown that an incremental failure set that emerges from a safe region can be written using only a pair of successive system instantaneous failure sets. The cumulative distribution function of soft failure is built by summing the incremental failure probabilities. A practical implementation of the proposed method can be manifest by first-order reliability methods (FORM) and second-order bounds. The proposed method can be used to assess initial quality and performance reliability of systems with combinations of designated means and tolerances. Examples of electro mechanical systems show the details of the formulation and the potential of the approach. Error sources and their magnitudes are discussed.
12
Tucan, Paul, Calin Vaida, Nicolae Plitea, Adrian Pisla, Giuseppe Carbone, and Doina Pisla. "Risk-Based Assessment Engineering of a Parallel Robot Used in Post-Stroke Upper Limb Rehabilitation." Sustainability 11, no. 10 (May 21, 2019): 2893. http://dx.doi.org/10.3390/su11102893.
Full textAbstract:
Recently, robotic-assisted stroke rehabilitation became an important research topic due to its capability to provide complex solutions to perform the customized rehabilitation motion with enhanced resources than the traditional rehabilitation. Involving robotic devices in the rehabilitation process would increase the number of possible rehabilitated patients, but placing the patient inside the workspace of the robot causes a series of risks that needs to be identified, analyzed and avoided. The goal of this work is to provide a reliable solution for an upper limb rehabilitation robotic structure designed as a result of a risk assessment process. The proposed approach implies a hazard identification process in terms of severity and probability, a failure mode and effects analysis to identify the possible malfunctions in the system and an AHP (Analytic Hierarchy Process) to prioritize the technical characteristics of the robotic structure. The results of the risk assessment process and of the AHP provide the base of the final design of the robotic structure, while another solution, in terms of minimizing the risk for the patient injury, is obtained using an external measuring system.
13
Pan, Xing, Lunhu Hu, Ziling Xin, Shenghan Zhou, Yanmei Lin, and Yong Wu. "Risk Scenario Generation Based on Importance Measure Analysis." Sustainability 10, no. 9 (September 7, 2018): 3207. http://dx.doi.org/10.3390/su10093207.
Full textAbstract:
A risk scenario is a combination of risk events that may result in system failure. Risk scenario analysis is an important part of system risk assessment and avoidance. In engineering activity-based systems, important risk scenarios are related to important events. Critical activities, meanwhile, mean risk events that may result in system failure. This article proposes these definitions of risk event and risk scenario based on the characteristics of risk in engineering activity-based systems. Under the proposed definitions, a risk scenario framework generated based on importance measure analysis is given, in which critical activities analysis, risk event identification, and risk scenario generation are the three main parts. Important risk events are identified according to activities’ uncertain importance measure and important risk scenarios are generated on the basis of a system’s critical activities analysis. In the risk scenario generation process based on importance analysis, the importance degrees of network activities are ranked to identify the subject of risk events, so that risk scenarios can be combined and generated by risk events and the importance of scenarios is analyzed. Critical activities are analyzed by Taguchi tolerance design, mathematical analysis, and Monte Carlo simulation methods. Then the degrees of uncertain importance measure of activities are solved by the three methods and these results are compared. The comparison results in the example show that the proposed method of uncertain importance measure is very effective for distinguishing the importance level of activities in systems. The calculation and simulation results also verify that the risk events composed of critical activities can generate risk scenarios.
14
Latcovich, John, Evangelos Michalopoulos, and Bernie Selig. "Risk-based Analysis Tools." Mechanical Engineering 120, no. 11 (November 1, 1998): 72–75. http://dx.doi.org/10.1115/1.1998-nov-3.
Full textAbstract:
American Society of Mechanical Engineering’s (ASME) risk-based inspection methodologies are being used to optimize and prioritize equipment overhaul and maintenance, and upgrade decisions. Hartford Steam Boiler Inspection and Insurance Co. (HSB) collaborated with ASME in developing these guidelines, and it used the ASME methodologies to develop its risk-based decision tools for steam turbine generators. The ASME Risk-Based Inspection Guidelines define five primary steps in developing risk-based programs. These are system definition, qualitative risk assessment, system assessment ranking, inspection program development, and economic optimization. In order to differentiate between turbines and generators in several types of service, the team designed a questionnaire that requires the owner or operator to identify equipment design features, monitoring capabilities, past operating and failure history, as well as current operating experience, inspection, and maintenance practices. The STRAP program is presently in the beta-testing phase, where 30 different turbines representing eight different manufacturers and three different industries have been analyzed. Full implementation of the program is expected to occur in the fall of 1998.
15
Tandon, Abhishek, Neha, Anu G. Aggarwal, and Ajay Jaiswal. "Reliability Assessment of Software System Using IFS and OWA-Tree Analysis." International Journal of Reliability, Quality and Safety Engineering 27, no. 05 (April 7, 2020): 2040013. http://dx.doi.org/10.1142/s0218539320400136.
Full textAbstract:
To address the software design and development, reliability assessment is considered as crucial and most important task. Several studies have been directed towards reliability assessment approaches for obtaining highly reliable software product. In conventional reliability theory, failure probability of any component is assumed as an exact value but in actuality it’s not possible to get failure probability precisely. In this study, we have proposed an approach to assess the reliability of a software system with vague failure rate of the components as the given information might be incomplete or uncertain. It is a bottom–top methodology which includes the combination of intuitionistic fuzzy set (IFS) theory and ordered weighted averaging (OWA) tree analysis. Using IFS, we are able to come over the vagueness in the failure rate data and by using OWA-tree, we incorporate the subjectivity in the opinion of software developers with respect to selection of module. Further, for the illustration of the proposed approach one numerical example has been discussed and software reliability is assessed based upon different orness level.
16
Min, Seungsik, and Hyeonae Jang. "Case Study of Expected Loss Failure Mode and Effect Analysis Model Based on Maintenance Data." Applied Sciences 11, no. 16 (August 10, 2021): 7349. http://dx.doi.org/10.3390/app11167349.
Full textAbstract:
Failure mode and effect analysis (FMEA) is one of the most widely employed pre-evaluation techniques to avoid risks during the product design and manufacturing phases. Risk priority number (RPN), a risk assessment indicator used in FMEA, is widely used in the field due to its simple calculation process, but its limitations as an absolute risk assessment indicator have been pointed out. There has also been criticism of the unstructured nature and lack of systematicity in the FMEA procedures. This work proposes an expected loss-FMEA (EL-FMEA) model that organizes FMEA procedures and structures quantitative risk assessment metrics. In the EL-FMEA model, collectible maintenance record data is defined and based on this, the failure rate of components and systems and downtime and uptime of the system are calculated. Moreover, based on these calculated values, the expected economic loss is computed considering the failure detection time. It also provides an alternative coefficient to evaluate whether or not a detection system is installed to improve the expected loss of failure. Finally, a case study was conducted based on the maintenance record data, and the application procedure of the EL-FMEA model was presented in detail, and the practicality of this model was verified through the results.
17
Akhavan, Peyman, Ali Shahabipour, and Reza Hosnavi. "A model for assessment of uncertainty in tacit knowledge acquisition." Journal of Knowledge Management 22, no. 2 (March 12, 2018): 413–31. http://dx.doi.org/10.1108/jkm-06-2017-0242.
Full textAbstract:
Purpose Expert systems have come to the forefront in the modeling of problems. One of the major problems facing the expert system designers is to develop an accurate knowledge base and a meaningful model of uncertainty associated with complex models. Decision-making is based on knowledge, and decision system support needs a knowledge base as well. An adequate knowledge acquisition (KA) process leads to accurate knowledge and improves the decision-making process. To manage the risk of a medical service (twin pregnancy in this case) a knowledge management system was created. The captured knowledge may be associated with an uncertainty. This study aims to introduce a method for evaluating the reliability of a tacit KA model. It assisted engineering managers in assessing and prioritizing risks. The study tried to use this method in risk management and new case in the health domain. Design/methodology/approach In this study, relevant variables were identified in the knowledge management literature reviews and the domain of expertise management. They are validated by a group of domain experts. Kendall’s W indicator was used to assess the degree of consensus. On the basis of combined cognitive maps, a cognitive network was constructed. Using Bayesian belief networks and fuzzy cognitive maps, an uncertainty assessment method of tacit KA was introduced. To help managers focus on major variables, a sensitivity analysis was conducted. Reliability of model was calculated for optimistic and pessimistic values. The applicability and efficacy of the proposed method were verified and validated with data from a medical university. Findings Results show that tacit KA uncertainty can be defined by independent variables, including environmental factors, personality and acquisition process factors. The reliability value shows the accuracy of the captured knowledge and the effectiveness of the acquisition process. The proposed uncertainty assessment method provides the reliability value of the acquisition model for knowledge engineers, so it can be used to implement the project and prevent failures in vital factors through necessary actions. If there is not a satisficed level of reliability, the KA project reliability can be improved by risk factors. The sensitivity analysis can help to select proper factors based on the resources. This approach mitigated some of the disadvantages of other risk evaluation methods. Originality/value The contribution of this study is to combine the uncertainty assessment with tacit KA based on fuzzy cognitive maps and the Bayesian belief networks approach. This approach used the capabilities of both narrative and computational approaches.
18
Ray, Asok, Min-Kuang Wu, Marc Carpino, and Carl F. Lorenzo. "Damage-Mitigating Control of Mechanical Systems: Part I—Conceptual Development and Model Formulation." Journal of Dynamic Systems, Measurement, and Control 116, no. 3 (September 1, 1994): 437–47. http://dx.doi.org/10.1115/1.2899239.
Full textAbstract:
A major goal in the control of complex mechanical systems such as advanced aircraft, spacecraft, and power plants is to achieve high performance with increased reliability, availability, component durability, and maintainability. The current state-of-the-art of control systems synthesis focuses on improving performance and diagnostic capabilities under constraints that often do not adequately represent the dynamic properties of the materials. The reason is that the traditional design is based upon the assumption of conventional materials with invariant characteristics. In view of high performance requirements and availability of improved materials, the lack of appropriate knowledge about the properties of these materials will lead to either less than achievable performance due to overly conservative design, or over-straining of the structure leading to unexpected failures and drastic reduction of the service life. The key idea of the research reported in this paper is that a significant improvement in service life can be achieved by a small reduction in the system dynamic performance. This requires augmentation of the current system-theoretic techniques for synthesis of decision and control laws with governing equations and inequality constraints that would model the properties of the materials for the purpose of damage representation and failure prognosis. The major challenge in this research is to characterize the damage generation process in a continuous-time setting, and then utilize this information for synthesizing algorithms of robust control, diagnostics, and risk assessment in complex mechanical systems. Damage mitigation for control of mechanical systems is reported in the two-part paper. The concept of damage mitigation is introduced and a continuous-time model of fatigue damage dynamics is formulated in this paper which is the first part. The second part which is a companion paper presents the synthesis of the open-loop control policy and the results of simulation experiments for transient operations of a reusable rocket engine.
19
Liu, Zhongzhi, Zhiwei Guo, Yongqing Li, Libao Zhu, and Chengqing Yuan. "An Improved Failure Risk Assessment Method for Bilge System of the Large Luxury Cruise Ship under Fire Accident Conditions." Journal of Marine Science and Engineering 9, no. 9 (September 3, 2021): 957. http://dx.doi.org/10.3390/jmse9090957.
Full textAbstract:
This paper develops an improved failure risk assessment method and discusses the risk control measures for a large luxury cruise ship’s bilge system under fire accident conditions. The proposed method incorporates an expert weight calculation model and a risk coefficient calculation model. The expert weight calculation model considers the differences in experts’ expertise levels (i.e., qualification level, decision-making capacity, and decision-making preference). Further, the method integrates the evaluations resulting from fuzzy analytic hierarchy process (FAHP) and extended fuzzy technique for order preference by similarity to ideal solution (FTOPSIS) of different experts. The risk coefficient (RC) calculation model utilizes a three-dimensional continuous matrix, serving to determine the risk factors’ ratings. The influences of the expert weight and RC calculation models on the proposed method’s performance are studied through a sensitivity analysis. The work demonstrates that the proposed method minimizes the issues encountered when using conventional methods for determining risk ratings. Finally, the results of an empirical study comprising ten experts evaluating the VISTA cruise ship’s bilge system prove the applicability of the proposed method and offer practical design guidelines to meet the regulations for Safe Return to Port (SRtP).
20
Wang, Yuan-Heng, Yung-Chia Hsu, Gene You, Ching-Lien Yen, and Chi-Ming Wang. "Flood Inundation Assessment Considering Hydrologic Conditions and Functionalities of Hydraulic Facilities." Water 10, no. 12 (December 19, 2018): 1879. http://dx.doi.org/10.3390/w10121879.
Full textAbstract:
This study proposed a two-phase risk analysis scheme for flood management considering flood inundation losses, including: (1) simplified qualitative-based risk analysis incorporating the principles of failure mode and effect analysis (FMEA) to identify all potential failure modes associated with candidate flood control measures, to formulate a remedial action plan aiming for mitigating the inundation risk within an engineering system; and (2) detailed quantitative-based risk analysis to employ numerical models to specify the consequences including flood extent and resulting losses. Conventional qualitative-based risk analysis methods have shown to be time-efficient but without quantitative information for decision making. However, quantitative-based risk analysis methods have shown to be time- and cost- consuming for a full spectrum investigation. The proposed scheme takes the advantages of both qualitative-based and quantitative-based approaches of time-efficient, cost-saving, objective and quantitative features for better flood management in term of expected loss. The proposed scheme was applied to evaluate the Chiang-Yuan Drainage system located on Lin-Bien River in southern Taiwan, as a case study. The remedial action plan given by the proposed scheme has shown to greatly reduce the inundation area in both highlands and lowlands. These measures was investigated to reduce the water volume in the inundation area by 0.2 million cubic meters, even in the scenario that the flood recurrence interval exceeded the normal (10-year) design standard. Our results showed that the high downstream water stage in the downstream boundary may increase the inundation area both in downstream and upstream and along the original drainage channel in the vicinity of the diversion. The selected measures given by the proposed scheme have shown to substantially reduce the flood risk and resulting loss, taking account of various scenarios: short duration precipitation, decreased channel conveyance, pump station failure and so forth.
21
Pinto, C. Ariel, Matthew Zurasky, Fatine Elakramine, Safae El Amrani, Raed M. Jaradat, Chad Kerr, and Vidanelage L. Dayarathna. "Enhancing Cyberweapon Effectiveness Methodology With SE Modeling Techniques." International Journal of Cyber Warfare and Terrorism 11, no. 3 (July 2021): 41–57. http://dx.doi.org/10.4018/ijcwt.2021070104.
Full textAbstract:
A recent cyberweapons effectiveness methodology clearly provides a parallel but distinct process from that of kinetic weapons – both for defense and offense purposes. This methodology promotes consistency and improves cyberweapon system evaluation accuracy – for both offensive and defensive postures. However, integrating this cyberweapons effectiveness methodology into the design phase and operations phase of weapons systems development is still a challenge. The paper explores several systems engineering modeling techniques (e.g., SysML) and how they can be leveraged towards an enhanced effectiveness methodology. It highlights how failure mode analyses (e.g., FMEA) can facilitate cyber damage determination and target assessment, how block and parametric diagraming techniques can facilitate characterizing cyberweapons and eventually assess the effectiveness of such weapons and conversely assess vulnerabilities of systems to certain types of cyberweapons.
22
Dinmohammadi, Fateme. "A risk-based modelling approach to maintenance optimization of railway rolling stock." Journal of Quality in Maintenance Engineering 25, no. 2 (May 7, 2019): 272–93. http://dx.doi.org/10.1108/jqme-11-2016-0070.
Full textAbstract:
Purpose Railway transport maintenance plays an important role in delivering safe, reliable and competitive transport services. An appropriate maintenance strategy not only reduces the assets’ lifecycle cost, but also will ensure high standards of safety and comfort for rail passengers and workers. In recent years, the majority of studies have been focused on the application of risk-based tools and techniques to maintenance decision making of railway infrastructure assets (such as tracks, bridges, etc.). The purpose of this paper is to present a risk-based modeling approach for the inspection and maintenance optimization of railway rolling stock components. Design/methodology/approach All the “potential failure modes and root causes” related to rolling stock systems are identified from an extensive literature review followed by an expert’s panel assessment. The failure causes are categorized into six groups of electrical faults, structural damages, functional failures, degradation, human errors and natural (external) hazards. Stochastic models are then proposed to estimate the likelihood (probability) of occurrence of a failure in the rolling stock system. The consequences of failures are also modeled by an “inflated cost function” that involves safety-related costs, corrective maintenance and renewal (M&R) costs, the penalty charges due to train delays or service interruptions as well as the costs associated with loss of reputation (or loss of fares) in the case of trip cancellation. Lastly, a time-varying risk-cost function is formulated to determine the optimal frequency of preventive inspection and maintenance actions for rolling stock components. Findings For the purpose of clearly illustrating the proposed risk-based inspection and maintenance modeling methodology, a case study of the Class 380 train’s pantograph system from a Scottish train operating company is provided. The results indicate that the proposed model has a substantial potential to reduce the M&R costs while ensuring a higher level of safety and service quality compared to the currently used inspection methodologies. Practical implications The railway rolling stocks should be regularly inspected and maintained so as to ensure network availability and reliability, passenger safety and comfort, and operations efficiency. Despite the best efforts of the maintenance staff, it is reported that a considerable amount of maintenance resources (e.g. budget, time, manpower) is wasted due to insufficiency or inefficiency of current periodic M&R interventions. The model presented in this paper helps the maintenance engineers to assess the current maintenance practices and propose or initiate improvement actions when needed. Originality/value There are few studies investigating the application of risk-based tools and techniques to inspection and maintenance decision making of railway rolling stock components. This paper presents a modeling approach aimed at planning the preventive repair and maintenance interventions for rolling stock components based on risk measures. The author’s model is also capable of incorporating real measurement information gathered at each inspection epoch to update future inspection plans.
23
Short, W. E. "Fire Versus Non-Fire Contingencies: A Study of Pressure-Relief Device Sizing Risks." Journal of Pressure Vessel Technology 128, no. 1 (October 26, 2005): 122–29. http://dx.doi.org/10.1115/1.2141638.
Full textAbstract:
There are tens of thousands of industrial manufacturing facilities operating throughout the world. Each chemical plant, petroleum refinery, pharmaceutical plant and other manufacturing facility has equipment and piping systems that operate under pressure. In the event of excessive overpressure, equipment or piping failures could result in economic loss to business, environmental contamination, and health and safety risks. To reduce such risks, equipment and piping systems that operate under pressure must be protected from excessive overpressure. This is accomplished with the installation of pressure-relief devices, which must be properly sized and specified for the intended service conditions. More specifically, overpressure protection is provided by pressure-relief devices that are sized, selected, specified and installed for the postulated governing overpressure contingency. To adequately size a pressure-relief device to provide overpressure protection for equipment and piping, several relief event scenarios always should be considered. In the U.S.A., federal and state regulations require operating industrial facilities to have risk management programs in place that include the design basis for safety-relief systems installed to protect pressurized equipment from overpressure. For new installations, the pressure-relief system design philosophy should be established during the project design phase. However, for process facilities that have been in operation for many years, the original design basis and calculations for the safety-relief devices often are no longer available. For existing pressure-relieving installations, fitness-for-service assessments should include verification of the relief device size and specification, and review and substantiation of required documentation. This paper presents results from a study intended to examine which overpressure relief contingency, if any, most often governs the size of relief devices that are used to protect equipment and piping systems. The required elements of a pressure-relieving system sizing and documentation program are described. The author emphasizes seven relief contingencies to be considered when sizing pressure-relief devices. Some restrictions and limitations of the codes and standards that are applied for design guidance of pressure-relieving systems are challenged. For this study, relief device sizing data was compiled from a number of chemical and petrochemical project applications to provide a reasonable sample of contingencies that governed the sizes of existing and new safety-relief valves and rupture disks. The study results show that a significant number of pressure-relief devices presently installed in the U.S.A. likely are undersized. This further suggests that, worldwide, an alarming number of pressure-relief devices may be undersized.
24
Zhou, Xiaomin, and Zheng Sun. "Quantitative assessment of landslide risk using Monte Carlo material point method." Engineering Computations 37, no. 5 (December 5, 2019): 1577–96. http://dx.doi.org/10.1108/ec-04-2019-0186.
Full textAbstract:
Purpose The purpose of this paper is to provide an effective way to assess landslide risk quantitatively. Quantitative assessment plays an important role in mitigating the landslide risk and developing a landslide risk-based warning system. However, efficient risk assessment on the large deformation failure process of slope with spatially variable soils is a challenging problem. Design/methodology/approach Combining the Monte Carlo simulation (MCS) and the higher-order material point method – the B-spline Material Point Method (BSMPM) – the concept of MC-BSMPM to assess the landslide risk quantitatively is proposed in this paper. The overall dynamic evolution of soil slope failure has been simulated by the BSMPM, and the probability density function of the sliding duration, the sliding kinematic energy, the sliding mass and the sliding distance of the landslide are obtained based on the MCS. Through the four risk assessment parameters of the sliding duration, the sliding kinematic energy, the sliding mass and the sliding distance, the landslide risk could be assessed quantitatively. Findings It is found that the post-failure behavior of the landslide conforms well to a normal distribution as the soil physical parameter is in a normal distribution. The variation of soil’s shear strength affects the dynamic motion of the landslide greatly. Originality/value The result shows that the landslide hazard cannot be estimated comprehensively by the deterministic BSMPM, while the landslide risk could be more clearly understood and quantitatively assessed with more details by the proposed method, which demonstrates that the MC-BSMPM method is an effective way to assess the landslide risk quantitatively.
25
SLOAN, JOHN C., TAGHI M. KHOSHGOFTAAR, PIERRE-PHILIPPE BEAUJEAN, and FREDERICK DRISCOLL. "OCEAN TURBINES — A RELIABILITY ASSESSMENT." International Journal of Reliability, Quality and Safety Engineering 16, no. 05 (October 2009): 413–33. http://dx.doi.org/10.1142/s0218539309003472.
Full textAbstract:
This paper identifies factors that impact reliability and safety of ocean turbines. We describe how physical and environmental factors will impact the design of its machine condition monitoring (MCM) system. Environmental factors like fouling, corrosion, and inaccessibility of equipment sets this MCM problem apart from those encountered by wind turbines, hydroelectric plants, or even ship hulls and propellers. Fouling constitutes the primary and most persistent source of failure. In addition to compromising turbine efficiency and reliability, fouling reduces sensor data quality — masking faults that will ultimately lead to failure. Unmitigated fouling triggers a form of biological succession known as flocculation that may eventually attract threatened species of tortoises and cetaceans to this rotating machinery. We review and suggest refinements to a class of non-toxic biologically-inspired anti-fouling techniques known as engineered topographies. Advances in this area will enable turbines to operate in portions of the water column that maximize momentum flux while minimizing retrieval cost.
26
Hernandez, Maria Del Pilar Colin, and Ashraf Labib. "Selecting a condition monitoring system for enhancing effectiveness of power transformer maintenance." Journal of Quality in Maintenance Engineering 23, no. 4 (October 9, 2017): 400–414. http://dx.doi.org/10.1108/jqme-07-2015-0027.
Full textAbstract:
Purpose The purpose of this paper is to propose a model for assisting in the decision-making process for acquiring a condition monitoring (CM) system for an oil-immersed power transformer in order to improve its maintainability. Design/methodology/approach The proposed model is based on the analytic hierarchy process. The assessment was performed by pairwise comparisons, and a sensitivity analysis (what-if analysis) was used to identify the implications of changing the criteria weights. In order to select the criteria and alternatives, a search was conducted for the power transformer failure modes, monitored parameters and CM technologies. Findings The proposed model provides a structured solution for a complex problem: deciding the best combination of technologies for CM of power transformers. Research limitations/implications Because the pairwise comparisons were done only by the author, the results may need to be improved with the assessment of more experts. Also, it was done for a specific type of transformer; it might be necessary to customise the alternatives for other cases. Finally, as a future consideration, more levels can be added to the hierarchy to improve the accuracy of the model. Practical implications The power transformer is an asset where the most appropriate maintenance strategy for it is condition-based maintenance. In order to improve its maintainability, it is recommendable to improve its testability and diagnosability. For achieving this goal, the maintenance personnel have to decide the best combination of technologies for CM. The methodology developed can assist the decision makers to select the most appropriate cost-benefit strategy. Originality/value The paper presents a structured and generic method of selecting the most appropriate CM system for power transformers.
27
Xu, Ning, Shuai Yuan, Xueqin Liu, Yuxian Ma, Wenqi Shi, and Dayong Zhang. "Risk assessment of sea ice disasters on fixed jacket platforms in Liaodong Bay." Natural Hazards and Earth System Sciences 20, no. 4 (April 24, 2020): 1107–21. http://dx.doi.org/10.5194/nhess-20-1107-2020.
Full textAbstract:
Abstract. Sea ice disasters seriously threaten the structural safety of oil platforms in the Bohai Sea. Therefore, it is necessary to carry out a risk assessment of sea ice disasters on oil platforms in the Bohai Sea. In this study, a risk assessment of sea ice disasters on fixed jacket platforms in Liaodong Bay, in the Bohai Sea, was performed in five steps. Firstly, the formation mechanisms of sea ice disasters were analyzed and the sources and modes of sea ice risks were summarized. Secondly, according to the calculation formulas of extreme ice force, dynamic ice force, and accumulated force, several ice indices such as thickness, motion, strength, period, and concentration were proposed as the hazard indices, and corresponding values were then assigned to the proposed indices based on ice conditions in the Bohai Sea. Thirdly, based on four structural failure modes – structural overturning by extreme ice force (Mode 1), structural fracture failure caused by dynamic ice force (Mode 2), the damage of facilities caused by dynamic ice force (Mode 3), and structural function failure caused by accumulated ice (Mode 4) – the structural vulnerability index, overturning index, dynamic index, ice-induced vibration index, and function index were proposed, and corresponding values were assigned to the structural vulnerability index of fixed jacket platforms in Liaodong Bay. Fourthly, the weight of each risk index was determined according to previously recorded sea ice disasters and accidents, and the sea ice risk was then calculated with the weighted synthetic index method. Finally, with the above index system and risk assessment methods, the risk assessment of sea ice disasters on 10 jacket platforms in three sea areas in Liaodong Bay was carried out. The analysis results showed that efficient sea ice prevention strategies could largely mitigate the sea ice-induced vibration-related risks of jacket platforms in Liaodong Bay. If steady-state vibration occurs (usually in front of the vertical legged structure) or the structural fundamental frequency is high, the structural vulnerability is significantly increased and the calculated risk levels are high. The sea ice risk assessment method can be applied in the design, operation, and management of other engineering structures in sea ice areas.
28
Hassan, Jakiul, Premkumar Thodi, and Faisal Khan. "Availability analysis of a LNG processing plant using the Markov process." Journal of Quality in Maintenance Engineering 22, no. 3 (August 8, 2016): 302–20. http://dx.doi.org/10.1108/jqme-05-2012-0018.
Full textAbstract:
Purpose – The purpose of this paper is to propose a state dependent stochastic Markov model for availability analysis of process plant instead of traditional time dependent model. Design/methodology/approach – The traditional concepts of system performance measurement and reliability (namely, binary; two-state concepts) are observed to be inadequate to characterize performance of complex system components. Availability analysis considering an intermediate state, such as a degraded state, provides a better alternative mechanism for system performance mapping. The availability model provides a better assessment of failure and repair characteristics for equipment in the sub-system and its overall performance. In addition to availability analysis, this paper also discusses the preventive maintenance (PM) program to achieve target availability. In this model, the degraded state is considered as a PM state. Using Markov analysis the optimum maintenance interval is determined. Findings – Markov process provides an easier way to measure the performance of the process facility. This study also revealed that the maintenance interval has a major influence in the availability of a process facility as well as in maintaining target availability. The developed model is also applicable to the varying target availability as well as having the capability to handle even the reconfigured process systems. Research limitations/implications – Considering the degraded state as an operative state, a higher availability of the plant is predicted. The consideration of the degraded state of the system makes the availability estimation more realistic and acceptable. Availability quantification, target availability allocation and a PM model are exemplified in a sub-system of an liquefied natural gas facility. Originality/value – The unique features of the present study are; Markov modeling approach integrating availability and PM; optimum PM interval determination of stochastically degrading components based on target availability; consideration of three-state systems; and consideration of increasing failure rates.
29
Zhu, Wei, Chen-yu Li, Xiao-yan Xiao, and Wen-bin Xu. "Diagnosing urban rail transit vehicles with FMEA and fuzzy set." Journal of Quality in Maintenance Engineering 21, no. 3 (August 10, 2015): 332–45. http://dx.doi.org/10.1108/jqme-08-2012-0026.
Full textAbstract:
Purpose – The purpose of this paper is to develop an effective treatment to analyze and diagnose urban rail transit (URT) vehicle maintenance strategy. Design/methodology/approach – In this paper, the technique of Failure Mode and Effects Analysis (FMEA) is introduced into the examination of URT trains, first. Then the method of fuzzy-set-based assessment for FMEA is presented, which is the quantitative tool of Fuzzy-Set-based treatment for FMEA in analysis and diagnoses to URT maintenance strategy. Moreover, recommendations for further improvement of the proposed approach are also provided. Initial application into the vehicle maintenance of Shanghai URT System shows, that the proposed approach has a good performance and consequently is worth further development. Findings – The paper presents a FMEA and fuzzy-set-based theoretical approach for analyzing and diagnosing current methods in URT vehicle maintenance strategy. Practical implications – With rapid development of URT systems in the world especially in those highly populated areas, much more attentions are turning to researches on URT maintenance, nevertheless, few quantitative research achievement are mentioned or applied. This paper is a tentative attempt at introducing fuzzy-set theory into quantitative analysis and diagnoses of URT maintenance strategy. Originality/value – The study in this paper is helpful in theory and practice of URT maintenance and its methodology could be further applied into a broad family of facility group or system in other engineering fields.
30
Boivin, Yannick, and Patrick Paultre. "Seismic performance of a 12-storey ductile concrete shear wall system designed according to the 2005National building code of Canadaand the 2004 Canadian Standard Association standard A23.3." Canadian Journal of Civil Engineering 37, no. 1 (January 2010): 1–16. http://dx.doi.org/10.1139/l09-115.
Full textAbstract:
This paper presents an assessment of the seismic performance of a ductile concrete core wall used as a seismic force resisting system for a 12-storey concrete office building in Montréal, designed according to the 2005 National building code of Canada (NBCC) and the 2004 Canadian Standards Association standard A23.3. The core wall consists of a cantilever wall system in one direction and a coupled wall system in the orthogonal direction. The building is analyzed in the nonlinear regime. The main conclusion from this work is that the capacity design shear envelope for the studied wall structure largely underestimates that predicted, primarily in the cantilever wall direction, and this in turn significantly increases the risk of shear failure. This issue is essentially due to (i) an underestimation by the new NBCC spectral response acceleration of the higher mode responses of a reinforced concrete wall structure whose seismic response is dominated by higher modes; and (ii) a deficiency in the capacity design method in estimating the wall shear demand on such walls, even when their behavior is lightly inelastic.
31
Battirola Filho, Julio Cesar, Flávio Piechnicki, Eduardo de Freitas Rocha Loures, and Eduardo Alves Portela Santos. "Process-aware FMEA framework for failure analysis in maintenance." Journal of Manufacturing Technology Management 28, no. 6 (July 3, 2017): 822–48. http://dx.doi.org/10.1108/jmtm-11-2016-0150.
Full textAbstract:
Purpose The purpose of this paper is to establish a Process-aware FMEA (PAFMEA) development environment in order to face the main Failure Mode Effect Analysis (FMEA) deficiencies concerning failure analysis in maintenance. Design/methodology/approach The proposed framework integrates Delphi methodology to obtain consensus of specialists’ opinions, analytic hierarchy process (AHP) to perform multiple criteria-based risk assessment and a business process management system to instantiate the development cycle. A conceptual model is presented and analyzed through a case study. Findings PAFMEA reveals a new perception in the evaluation and prioritization of failure modes during maintenance failure analysis, such as risk definition and resource availability, dealing with conflicting characteristics in decision-making approaches. Practical implications The PAFMEA environment includes requirements that are grouped with a process instantiation of an AHP structure, providing a high degree of applicability and performance to the development cycles of the FMEA. The new method confronts the classical risk assessment approach and contributes to the literature, adding new perspectives to the FMEA analysis. Originality/value PAFMEA brings new and promising perspectives to the FMEA development cycle, which, in short, means adding on a multi-criteria failure analysis method (AHP) through a process-aware platform, with performance impacts in FMEA knowledge sharing, decision making and delivery.
32
Kucuk Yilmaz, Ayse. "Strategic approach to managing human factors risk in aircraft maintenance organization: risk mapping." Aircraft Engineering and Aerospace Technology 91, no. 4 (April 1, 2019): 654–68. http://dx.doi.org/10.1108/aeat-06-2018-0160.
Full textAbstract:
Purpose Aviation has multi-cultural business environment in all aspects as operational and management. Managing aviation requires high awareness on human factor risk which includes organizational behavior-related topics. The greatest risk to an enterprise’s ability to achieve its strategic goals and objectives is the human factor. Both organizational behavior and corporate culture behavior with social psychology are the most vital aspects of management and strategy in terms of human resources. Related risks, including organizational behavior and culture, have the potential to directly impact on both business performance and corporate sustainability. Therefore, in this paper, the most prominent risks were determined in accordance with social psychology, and after identification of human factor-based risks, these have prioritized and prepared risk mapping with fresh approach. For this reason, this study aims to develop risk mapping model for human factors that takes into account interrelations among risk factors three dimensional based new approach. This approach includes both identification of human factor based risks, prioritization them and setting risk mapping according to corporate based qualifications via tailoring risk list. Developed risk map in this paper will help to manage corporate risks to achieve improved performance and sustainability. Design/methodology/approach This new organizational behavior- and culture-focused risk mapping model developed in this study has the potential to make significant contribution to the management of the human factor for modern management and strategy. In enterprise risk management system, risk mapping is both strong and effective strategic methodology to manage ergonomics issue with strategic approach. Human factor is both determinative and also strategic element to both continuity and performance of business operations with safely and sound. In view of management and strategy, vitally, the human factor determines the outcome in both every business and every decision-making. Findings It is assumed that, if managers manage human risk you may get advantages to achieving corporate strategies in timely manner. Aviation is sensitive sector for its ingredients: airports, airlines, air traffic management, aircraft maintenance, pilotage and ground handling. Aim of this paper is to present risk management approach to optimize human performance while minimizing both failures and errors by aircraft maintenance technician (AMT). This model may apply all human factors in other departments of aviation such as pilots and traffic controllers. AMT is key component of aircraft maintenance. Thus, errors made by AMTs will cause aircraft accidents or incidents or near miss incidents. In this study, new taxonomy model for human risk factors in aircraft maintenance organizations has been designed, and also new qualitative risk assessment as three dimensions is carried out by considering the factors affecting the AMT’s error obtained from extensive literature review and expert opinions in the field of aviation. Human error risks are first categorized into two main groups and sub three groups and then prioritized using the risk matrix via triple dimension as probability, severity and interrelations ratio between risks. Practical implications Risk mapping is established to decide which risk management option they will apply for managers when they will look at this map. Managers may use risk map to both identify their managerial priorities and share sources to managing risks, and make decisions on risk handling options. This new model may be a useful new tool to manage ergonomic human factor-based risks in developing strategy in aviation business management. In addition, this paper will contribute to department of management and strategy and related literature. Originality/value This study has originality via new modeling of risk matrix. In this study, dimension of risk analysis has been improved as three dimensions. This study has new approach and new assessment of risk with likelihood (probability), impact (severity) and interrelations ratio. This new model may be a useful new tool to both assess and prioritize mapping of ergonomic-based risks in business management. In addition, this research will contribute to aviation management and strategy literature and also enterprise risk management literature.
33
Frazier, James A., and John L. Henneman. "Project-Level Air Quality Assessment Actions: Interrelating Conformity with National Environmental Policy Act Process." Transportation Research Record: Journal of the Transportation Research Board 1520, no. 1 (January 1996): 3–10. http://dx.doi.org/10.1177/0361198196152000101.
Full textAbstract:
The procedural aspect of linking the transportation conformity process and the transportation alternatives development process that is part of the National Environmental Policy Act (NEPA) is discussed. The linkage is structured to ensure continuity between project-level design considerations developed during planning and programming and refined as part of the NEPA process. These issues are critical to the Pennsylvania Department of Transportation, Bureau of Environmental Quality, where air quality impacts delineated during the conformity process play a significant role in the continued development and refinement of the transportation system. For states like Pennsylvania, where transportation conformity requirements play a strong role in the transportation development process, providing a single set of air quality assessment actions can avoid the risk of conformity reevaluation or failure caused by project redesign during the NEPA process. A method to link the regional transportation conformity air quality analysis with project development and design conducted during the NEPA process is described. The linkage is made by using project-level air quality impacts developed during the regional conformity analysis and comparing the air quality impacts of transportation alternatives as they are developed during the NEPA process. Elements of the air quality impacts delineated during the regional conformity analysis act as the project-level air quality benchmark that is carried forward into the NEPA process.
34
Zhemchugov-Gitman, Dmitry M., Lyubov V. Mozzhukhina, and Alexander M. Uzdin. "On the question of setting the level of calculated impact and reliability of high-rise construction." Earthquake Engineering. Construction Safety, no. 1 (February 25, 2021): 43–56. http://dx.doi.org/10.37153/2618-9283-2021-1-43-56.
Full textAbstract:
The question of setting the seismic design input
on high rise buildings is considered. The existing approaches to accounting for
increased responsibility of high rise buildings in Russia are described. The
proposal to reduce the probability of an acceptable building failure in
proportion to the number of floors and Guideline proposals to increase the
reliability factor and using maps of general seismic zoning are analyzed. The
main disadvantages of methods described are indicated. It is shown that the current
regulatory documents in the field of earthquake engineering do not provide the
same reliability of designed structures in general and high-rise buildings in
particular. The influence of seismic dangers in according with seismic zoning
maps on the reliability of the designed objects is noted. An approach to
generating the design input based on the permissible probability of its
exceeding is considered using the example of five five-storey buildings and one
25-storey buildings. The probability of the admissible damage value included in
the normative calculations is estimated. An estimate of the allowable failure
probability on the value of acceptable damage (risk) is proposed under the
assumption of a normal distribution of damage caused by earthquake. It is shown
that the allowable failure probability decreases with decreasing acceptable
damage only in the area of small damages. An approach to the assignment of
seismic action based on an assessment of seismic risk has been formulated. The
system of design coefficients used to calculate seismic loads on high-rise
buildings is analyzed. It is noted that along with an increase in the design
level of seismic acceleration, it is necessary to increase the coefficient,
taking into account the low damping of high-rise buildings oscillations. At the
same time, it is possible to significantly reduce the reduction coefficient by
regulating the strains between the building floors.
35
Kaliatka, Algirdas, Eugenijus Uspuras, and Sigitas Rimkevicius. "Relap5 Analysis of Processes in Reactor Cooling Circuit and Reactor Cavity in Case of Station Blackout in RBMK-1500." Science and Technology of Nuclear Installations 2007 (2007): 1–9. http://dx.doi.org/10.1155/2007/52850.
Full textAbstract:
Ignalina NPP is equipped with channel-type boiling-water graphite-moderated reactor RBMK-1500. Results of the level-1 probabilistic safety assessment of the Ignalina NPP have shown that in topography of the risk, the transients with failure of long-term core cooling other than LOCA are the main contributors to the core damage frequency. The total loss of off-site power with a failure to start any diesel generator, that is station blackout, is the event which could lead to the loss of long-term core cooling. Such accident could lead to multiple ruptures of fuel channels with severe consequences and should be analyzed in order to estimate the timing of the key events and the possibilities for accident management. This paper presents the results of the analysis of station blackout at Ignalina NPP. Analysis was performed using thermal-hydraulic state-of-the-art RELAP5/MOD3.2 code. The response of reactor cooling system and the processes in the reactor cavity and its venting system in case of a few fuel-channel ruptures due to overheating were demonstrated. The possible measures for prevention of the development of this beyond design basis accident (BDBA) to a severe accident are discussed.
36
Abdulai, Musah, and Mostafa Sharifzadeh. "Probability Methods for Stability Design of Open Pit Rock Slopes: An Overview." Geosciences 11, no. 8 (July 28, 2021): 319. http://dx.doi.org/10.3390/geosciences11080319.
Full textAbstract:
The rock slope stability analysis can be performed using deterministic and probabilistic approaches. The deterministic analysis based on the safety concept factor uses fixed representative values for each input parameter involved without considering the variability and uncertainty of the rock mass properties. Probabilistic analysis with the calculation of probability of failure instead of the factor of safety against failure is emerging in practice. Such analyses offer a more rational approach to quantify risk by incorporating uncertainty in the input variables and evaluating the probability of the failure of a system. In rock slope engineering, uncertainty and variability involve a large scatter of geo-structural data and varied geomechanical test results. There has been extensive reliability analysis of rock slope stability in the literature, and different methods of reliability are being employed for assessment of the probability of failure and the reliability of a slope. Probabilistic approaches include Monte Carlo simulation (MCS), the point estimate method (PEM), the response surface method (RSM), first- and second-order reliability methods (FORMs and SORMs), and the first-order second-moment method (FOSM). Although these methods may be complicated, they provide a more complete definition of risk. Probabilistic slope stability analysis is an option in most commercial software; however, the use of this method is not common in practice. This paper provides an overview of the literature on some of the main probabilistic reliability-based methods available for the design of the rock slope in open pit mining. To demonstrate its applicability, the paper investigates the stability of a rock slope in an open pit mine in the Goldfields region, Western Australia. Two different approaches were adopted: deterministic stability analysis using two-dimensional limit equilibrium and finite element shear strength reduction methods using SLIDE and RS2 software, respectively, and probabilistic analysis by applying the MCS and RSM methods in the limit equilibrium method. In this example, the slope stability analysis was performed using the Spencer method with Cuckoo search optimization to locate the critical slip surface. The results obtained were compared and commented on.
37
Singh, Salvinder, and Shahrum Abdullah. "Durability analysis using Markov chain modeling under random loading for automobile crankshaft." International Journal of Structural Integrity 10, no. 4 (August 12, 2019): 454–68. http://dx.doi.org/10.1108/ijsi-03-2018-0016.
Full textAbstract:
Purpose The purpose of this paper is to present the durability analysis in predicting the reliability life cycle for an automobile crankshaft under random stress load using the stochastic process. Due to the limitations associated with the actual loading history obtained from the experimental analysis or due to the sensitivity of the strain gauge, the fatigue reliability life cycle assessment has lower accuracy and efficiency for fatigue life prediction. Design/methodology/approach The proposed Markov process embeds the actual maximum and minimum stresses by a continuous updating process for stress load history data. This is to reduce the large credible intervals and missing loading points used for fatigue life prediction. With the reduction and missing loading intervals, the accuracy of fatigue life prediction for the crankshaft was validated using the statistical correlation properties. Findings It was observed that fatigue reliability corresponded well by reporting the accuracy of 95–98 per cent with a mean squared error of 1.5–3 per cent for durability and mean cycle to failure. Hence, the proposed fatigue reliability assessment provides an accurate, efficient, fast and cost-effective durability analysis in contrast to costly and lengthy experimental techniques. Research limitations/implications An important implication of this study is durability-based life cycle assessment by developing the reliability and hazard rate index under random stress loading using the stochastic technique in modeling for improving the sensitivity of the strain gauge. Practical implications The durability analysis is one of the fundamental attributes for the safe operation of any component, especially in the automotive industry. Focusing on safety, structural health monitoring aims at the quantification of the probability of failure under mixed mode loading. In practice, diverse types of protective barriers are placed as safeguards from the hazard posed by the system operation. Social implications Durability analysis has the ability to deal with the longevity and dependability of parts, products and systems in any industry. More poignantly, it is about controlling risk whereby engineering incorporates a wide variety of analytical techniques designed to help engineers understand the failure modes and patterns of these parts, products and systems. This would enable the automotive industry to improve design and increase the life cycle with the durability assessment field focussing on product reliability and sustainability assurance. Originality/value The accuracy of the simulated fatigue life was statistically correlated with a 95 per cent boundary condition towards the actual fatigue through the validation process using finite element analysis. Furthermore, the embedded Markov process has high accuracy in generating synthetic load history for the fatigue life cycle assessment. More importantly, the fatigue reliability life cycle assessment can be performed with high accuracy and efficiency in assessing the integrity of the component regarding structural integrity.
38
Si, Qing Min, Xing Bai Zhang, Xue Ying Jiang, Lei Tian, and Gong Xin Yu. "Urban Power Supply System Risk Assessment." Advanced Materials Research 960-961 (June 2014): 1508–11. http://dx.doi.org/10.4028/www.scientific.net/amr.960-961.1508.
Full textAbstract:
Urban power supply system has close relationship with urban public safety. The main risk factors, accident types and the risk degree of failures or accidents in urban power supply system are analyzed. And, it has established the public safety risk assessment system of urban power supply system. In order to show that the assessment system has good applicability in the risk assessment of urban power supply system, the power supply system safety of one urban is assessed using established risk assessment system.
39
Saatlou, E. Najafi, KG Kyprianidis, V. Sethi, AO Abu, and P. Pilidis. "On the trade-off between minimum fuel burn and maximum time between overhaul for an intercooled aeroengine." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 228, no. 13 (January 15, 2014): 2424–38. http://dx.doi.org/10.1177/0954410013518509.
Full textAbstract:
A large variety of promising power and propulsion system concepts are being proposed to reduce carbon dioxide and other emissions. However, the best candidate to pursue is difficult to select and it is imperative that major investments are correctly targeted to deliver environmentally friendly, economical and reliable solutions. To conceive and assess gas turbine engines with minimum environmental impact and lowest cost of ownership in a variety of emission legislation scenarios and emissions taxation policies, a tool based on a techno-economic and environmental risk assessment methodology is required. A tool based on this approach has been developed by the authors. The core of the tool is a detailed and rigorous thermodynamic representation of power plants, around which other modules can be coupled (that model different disciplines such as aircraft performance, economics, emissions, noise, weight and cost) resulting in a multidisciplinary framework. This approach can be used for efficient and cost-effective design space exploration in the civil aviation, power generation, marine, and oil and gas fields. In the present work, a conceptual intercooled core aeroengine design was assessed with component technologies consistent with 2020 entry into service via a multidisciplinary optimisation approach. Such an approach is necessary to assess the trade-off between asset life, operating costs and technical specification. This paper examines the influence of fuel consumption, engine weight and direct operating costs with respect to extending the engine life. The principal modes of failure such as creep, fatigue and oxidation, are considered in the engine life estimation. Multidisciplinary optimisation, comprising the main engine design parameters, was carried out with maximum time between overhaul as the objective function. The trade-off between minimum block fuel burn and maximum engine life was examined; the results were compared against the initial engine design and an assessment was made to identify the design changes required for obtaining an improved engine design in terms of direct operating costs. The results obtained from the study demonstrate that an engine optimised for maximum time between overhaul requires a lower overall pressure ratio and specific thrust but this comes at the cost of lower thermal efficiency and higher engine production costs.
40
Nicholds, Boyd Alexander, and John P. T. Mo. "Reliability analysis of productivity enhancement initiatives." Journal of Manufacturing Technology Management 29, no. 6 (October 15, 2018): 1003–24. http://dx.doi.org/10.1108/jmtm-12-2016-0187.
Full textAbstract:
Purpose Process improvement (PI) projects in manufacturing suffer from high failure rates, often due to management capability overstretch. An organisation’s management may be unaware that they lack the necessary capability to achieve desired performance gains from a particular PI project. As a consequence, PI projects containing a level of complexity are undertaken but the organisation is not capable of providing the required resources. The purpose of this paper is to develop a new method for assessing whether a productivity enhancement initiative which develops into PI projects have a good probability of success (POS). The risk assessment method predicts the POS in achieving desired performance targets from a PI project. Design/methodology/approach The POS of a system can be measured in terms of reliability. An operation with a high POS indicates high reliability of the system’s ability to perform. Reliability is a form of risk assessment. When applied to PI projects, several key factors should be addressed. First, risk should be modelled with a framework that includes human factors. Second, time is an important dimension due to the need for persistence in effort. This research proposes the concept of performance effectiveness function, kP, that links the capability of an organisation with its performance level. A PI reliability function indicating the probably of success of the PI projects can then be derived at the design stage by combining the capability score and actual performance. Findings The PI reliability function has been developed and tested with an industry case in which a PI project is planned. The analysis indicates that the company is far from ideal to do the project. Research limitations/implications The reliability function may be used as a decision support tool to assist decision makers to set realistic performance gain targets from PI projects. The data set for deriving the function came from automotive and metal industries. Further research is required to generalise this methodology to other industries. Practical implications The reliability-based approach fills the gap in PI literature with a more holistic approach to determine the POS. Using the system’s reliability as an indicator, decision makers can analyse the system’s design so that resources can be used to increase key capabilities and hence the overall system’s POS can be increased more effectively. Social implications Many manufacturing organisations are looking to improve their operations by projects that aim to reduce waste in their operations. However, researches show that while achieving desired performance gain from PI is possible, it is by no means certain due to human factors. This research provides a decision support tool that evaluates human factors as well. Originality/value The originality lies in integration of the reliability theory to PI risk assessment and the novel method of characterising organisational capabilities to work towards meeting desired performance targets from manufacturing PI projects. This work has good potential to generalise for estimating the POS of other types of development projects.
41
France, Daniel, Paromita Nath, Sankaran Mahadevan, Jason Slagle, Rajiv Agarwal, Zachary Kohutek, Erin Alexis Gillaspie, et al. "Using Fitbit data to predict clinical deterioration and unplanned treatment events in cancer outpatients." Journal of Clinical Oncology 39, no. 15_suppl (May 20, 2021): e13560-e13560. http://dx.doi.org/10.1200/jco.2021.39.15_suppl.e13560.
Full textAbstract:
e13560 Background: A common cause of preventable harm is the failure to detect and appropriately respond to clinical deterioration. Timely intervention is needed, particularly in cancer patients, to mitigate the effects of adverse events, disease progression, and medical error. This problem requires effective clinical surveillance, early recognition, timely notification of the appropriate clinician, and effective intervention. Methods: Applying a user-centered systems engineering design approach, we designed and implemented a surveillance-and-response system to improve the detection and response to clinical deterioration in cancer outpatients. The surveillance system predicts 7-day risk of UTEs, defined as clinically meaningful changes in the patient’s treatment course or cancer care pathway (e.g., any unplanned/unexpected: clinic or ER visit, hospital admission, or major treatment change and/or delays, and/or death). Data inputs consist of: 1) patient activity and health data collected by a Fitbit monitor; 2) geolocation data to measure activity outside the home (i.e., locations preselected at study onset); 3) clinical data from the hospital’s electronic health record; and 4) patient-reported outcomes measures (i.e., PROMs; the NCCN Distress Thermometer, the Comprehensive OpeN-Ended Survey or CONES, Global Health Score, items from the Consumer Assessment of Healthcare Providers and Systems (CAHPS)). Herein, we measured the effectiveness of Fitbit data alone to UTEs in a pilot sample of patients. Dimension reduction of Fitbit variables was first carried out by using Pearson correlation analysis to eliminate redundant variables. As UTEs are rare events, they were oversampled using the Synthetic Minority Oversampling Technique (SMOTE) to balance the dataset. A random forest classification model was trained to predict 7-day UTE risk. Model accuracy was determined by calculating the mean of Stratified 5-Fold Cross-Validation with 10 repeats. Results: Fitbit data was collected over a 6-8-week period from 14 head and neck cancer patients receiving surgical resection, outpatient chemotherapy, and/or radiotherapy. We identified six UTEs in 5 patients. A random forest classification model was developed from 10 variables derived from 7 Fitbit measures. The following variables were averaged or summed daily: average heart rate (HR), resting HR, below 50% or zone 1 of maximum HR, zone 2 and zone 3 HR combined (i.e., 70-100% of max HR), total daily calories, steps, and sleep in minutes. We achieved a model accuracy of 94% (ROC AUC: 0.984, Precision-Recall AUC: 0.985). Conclusions: Activity and health data collected by a commercial activity monitor demonstrated effectiveness in predicting patient UTEs when an oversampling procedure was used to adjust for class imbalance (i.e., low UTE rate). Future studies are recommended to verify and validate this result in a larger patient sample.
42
Zarghami, Seyed Ashkan, and Indra Gunawan. "A fuzzy-based vulnerability assessment model for infrastructure networks incorporating reliability and centrality." Engineering, Construction and Architectural Management 27, no. 3 (October 9, 2019): 725–44. http://dx.doi.org/10.1108/ecam-10-2018-0437.
Full textAbstract:
Purpose The purpose of this paper is to attempt to shift away from an exclusive probabilistic viewpoint or a pure network theory-based perspective for vulnerability assessment of infrastructure networks (INs), toward an integrated framework that accounts for joint considerations of the consequences of component failure as well as the component reliability. Design/methodology/approach This work introduces a fuzzy inference system (FIS) model that deals with the problem of vulnerability analysis by mapping reliability and centrality to vulnerability. In the presented model, reliability and centrality are first fuzzified, then 16 different rules are defined and finally, a defuzzification process is conducted to obtain the model output, termed the vulnerability score. The FIS model developed herein attempts to explain the linkage between reliability and centrality so as to evaluate the degree of vulnerability for INs elements. Findings This paper compared the effectiveness of the vulnerability score in criticality ranking of the components against the conventional vulnerability analysis methods. Comparison of the output of the proposed FIS model with the conventional vulnerability indices reveals the effectiveness of the vulnerability score in identifying the criticality of components. The model result showed the vulnerability score decreases by increasing reliability and decreasing centrality. Practical implications Two key practical implications for vulnerability analysis of INs can be drawn from the suggested FIS model in this research. First, the maintenance strategy based on the vulnerability analysis proposed herein will provide an expert facilitator that helps infrastructure utilities to identify and prioritize the vulnerabilities. The second practical implication is especially valuable for designing an effective risk management framework, which allows for least cost decisions to be made for the protection of INs. Originality/value As part of the first contribution, we propose a novel fuzzy-based vulnerability assessment model in building a qualitative and quantitative picture of the vulnerability of INs. The second contribution is especially valuable for vulnerability analysis of INs by virtue of offering a key to understanding the component vulnerability principle as being constituted by the component likely behavior as well as the component importance in the network.
43
Fei, Teng, and Hao-Wei Wang. "Reliability Demonstration Method for Competing Failure System." International Journal of Reliability, Quality and Safety Engineering 27, no. 04 (April 7, 2020): 2050015. http://dx.doi.org/10.1142/s0218539320500151.
Full textAbstract:
In order to improve the accuracy of reliability assessment for the system with multiple failure modes, a reliability modeling method based on the s-dependent competing risk of degradation failures and traumatic failures was proposed. A condition space model was applied to evaluate the degradation degree of system by fusing multivariate degradation data, and then Gamma process was utilized to establish the degradation failure model of system. A conditional Weibull distribution was used to establish the traumatic failure model of system. The reliability model based on dependent competing risk was established by assuming that the probability of traumatic failure depends on the degradation degree of system. An illustrative example was provided to validate the effectiveness of the proposed method.
44
Feng, Jing, Ying Wang, and Xian Yong Xiao. "Synthetic Risk Assessment of Catastrophic Failures in Power System Based on Entropy Weight Method." Advanced Materials Research 446-449 (January 2012): 3015–18. http://dx.doi.org/10.4028/scientific5/amr.446-449.3015.
Full text
45
Valentinov, Vladislav, Stefan Hielscher, Sebastian Everding, and Ingo Pies. "The anti-GMO advocacy: an institutionalist and systems-theoretic assessment." Kybernetes 48, no. 5 (May 7, 2019): 888–905. http://dx.doi.org/10.1108/k-01-2018-0016.
Full textAbstract:
Purpose Public debates on the use of genetically modified organisms (GMOs) are strongly influenced by the nongovernmental organization (NGO)-led advocacy, most of which is harshly critical of genetic engineering. This advocacy has resulted in discourse failures marked by the disregard for the scientific consensus on the risks and benefits of GMOs. This paper aims to present a theoretical inquiry into this phenomenon. Design/methodology/approach Drawing on American institutionalism and Niklas Luhmann social systems theory, the paper explains these discourse failures in terms of the problematic relationship between institutions and technology. Findings Clarence Ayres would likely see these discourse failures as a form of “institutional resistance” to the progress of science and technology. In contrast, Marc Tool’s social value principle stresses the importance of democratic legitimation and public acceptance of new technologies, while being sensitive to the possibility of ideologically biased discourses. It is argued that the institutionalist understanding of the interplay between democracy, science and technology would benefit from a better account of Niklas Luhmann’s concept of “complexity reduction”. Social implications The study shows that some NGOs are powerful enough to actively shape, if not manipulate, public attitudes and sentiments against GMOs. Originality/value The case of the anti-GMO advocacy calls for a new conceptualization of how democracy, science and technology fit together.
46
Whitehead, J. H., and A. Leventhal. "On-site wastewater management system design and landslide risk assessment." Water Science and Technology 51, no. 10 (May 1, 2005): 55–63. http://dx.doi.org/10.2166/wst.2005.0351.
Full textAbstract:
On-site wastewater management system design and performance is significant in assessing landslide risk in areas with potential for slope instability. Much of the development in Pittwater, NSW, local government area is on steep coastal land which has a history of slope instability. Concern over cases of poorly performing or failing on-site wastewater systems and the recognition that these and newly designed systems could be contributory to slope instability has been a factor in Pittwater Council, NSW, requiring that landslide risk assessment be undertaken for new and amended on-site wastewater management systems in potentially unstable areas. This paper describes the wastewater management system design and landslide risk assessment undertaken at Pittwater Youth Hostel in accordance with the Australian Geomechanics Society's Geotechnical Risk Management procedure to comply with the Pittwater Policy. The work completed illustrates both necessary and effective interaction of the wastewater and geotechnical professions to achieve a successful outcome for the client. It is likely that this professional interaction will be increasingly common along the NSW coast and elsewhere.
47
Marquez, Andres, C. Jagroop, and C. Maharaj. "Wastewater collection system failures in a capital city: analysis and sustainable prevention." Water Science and Technology 83, no. 8 (March 19, 2021): 1958–72. http://dx.doi.org/10.2166/wst.2021.105.
Full textAbstract:
Abstract An analysis of failures in a capital city's wastewater collection system was carried out and recommendations were made for sustainable preventive measures based on a risk of failure assessment. Most failures in sewer lines were associated with blockage caused by sediment accumulation and clogging from fats, oils and/or grease dumped by restaurants along several streets, combined with poor or nonexistent maintenance of the lines. Sewer lines in streets with higher risk levels due to multiple food establishments along those streets experienced most of the failures. Sustainability of the proposed maintenance was evidenced since it reduces costs and exposure to harmful substances and hazardous conditions as well as minimizing environmental impacts.
48
Kale, Nachiket Vinayak, Firat Ilkay, and Oliver Zysk. "Particular risk analysis: impact on hybrid aircraft design." International Journal of Structural Integrity 6, no. 3 (June 8, 2015): 402–9. http://dx.doi.org/10.1108/ijsi-10-2014-0060.
Full textAbstract:
Purpose – This document presents a Particular Risks Assessment (PRA) performed on an Uncontained Engine Rotor Failure (UERF) event for the new aircraft design hybrid Extremely Short Take Off and Landing All Surface (ESTOLAS) aircraft. All three propellers of the ESTOLAS (one hub propeller and two feed propellers) are evaluated for their impact on the aircraft in case of an UERF. The purpose of this paper is to present an illustration of the safety analysis and its requirement in new aircraft development. Design/methodology/approach – The methodology used is in accordance with the aerospace industry safety standard Society of Automobile Engineers (SAE) Aerospace Recommended Practices (ARP) 4,761 (Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment). Trajectory analyses are used on a digital mock-up of the aircraft to simulate the movement of the propeller blade fragments and its effect on the aircraft and its systems. Findings – The paper provides an insight into the industry practice of performing PRA on new aircraft designs. The study identifies safe and unsafe regions of the aircraft, with the UERF event in mind. Technical solutions are suggested to minimize the damage to the aircraft and its systems. Originality/value – This document fulfills the originality criterion, since it is an analysis performed on a new aircraft design – the ESTOLAS.
49
Roy, Soumen Kumar, A. K. Sarkar, and Biswajit Mahanty. "Fuzzy risk assessment for electro-optical target tracker." International Journal of Quality & Reliability Management 33, no. 6 (June 6, 2016): 830–51. http://dx.doi.org/10.1108/ijqrm-03-2015-0034.
Full textAbstract:
Purpose – The purpose of this paper is to evolve a guideline for scientists and development engineers to the failure behavior of electro-optical target tracker system (EOTTS) using fuzzy methodology leading to success of short-range homing guided missile (SRHGM) in which this critical subsystems is exploited. Design/methodology/approach – Technology index (TI) and fuzzy failure mode effect analysis (FMEA) are used to build an integrated framework to facilitate the system technology assessment and failure modes. Failure mode analysis is carried out for the system using data gathered from technical experts involved in design and realization of the EOTTS. In order to circumvent the limitations of the traditional failure mode effects and criticality analysis (FMECA), fuzzy FMCEA is adopted for the prioritization of the risks. FMEA parameters – severity, occurrence and detection are fuzzifed with suitable membership functions. These membership functions are used to define failure modes. Open source linear programming solver is used to solve linear equations. Findings – It is found that EOTTS has the highest TI among the major technologies used in the SRHGM. Fuzzy risk priority numbers (FRPN) for all important failure modes of the EOTTS are calculated and the failure modes are ranked to arrive at important monitoring points during design and development of the weapon system. Originality/value – This paper integrates the use of TI, fuzzy logic and experts’ database with FMEA toward assisting the scientists and engineers while conducting failure mode and effect analysis to prioritize failures toward taking corrective measure during the design and development of EOTTS.
50
Clarhaut, J., V. Cocquempot, B. Conrard, and S. Hayat. "Optimal Design of Dependable Control System Architectures Using Temporal Sequences of Failures." IEEE Transactions on Reliability 58, no. 3 (September 2009): 511–22. http://dx.doi.org/10.1109/tr.2009.2026790.
Full text