Dissertations / Theses on the topic 'Schedule maintenance'

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Os parques eólicos devem periodicamente desligar suas turbinas para realizar as manutenções agendadas. Uma vez que esta interrupção afeta a geração de energia e qualquer déficit na produção deve ser coberto por compras de energia no mercado spot, determinar o tempo ótimo para iniciar o trabalho de manutenção em um parque eólico é fundamental para maximizar sua receita, considerando que é função tanto da velocidade do vento esperada como dos preços spot da eletricidade. Neste trabalho, desenvolvemos um modelo para determinar o momento ideal para manutenção em um parque eólico. Analisamos uma janela de oportunidade no período mais provável do ano e realizamos atualizações semanais das velocidades esperadas do vento e previsões de preços de energia. As velocidades do vento são previstas com um modelo ARIMA enquanto os preços spot são simulados sob o modelo de programação estocástica dupla Newave. A decisão de adiar a manutenção para uma data futura é modelada como uma opção real americana. Testamos dois modelos com dados reais de um parque eólico no Nordeste brasileiro e comparamos nossos resultados com a prática atual e com o agendamento de manutenção considerando informações perfeitas para determinar os benefícios do modelo. Os resultados sugerem que esses modelos podem oferecer vantagens significativas em relação a uma decisão de parada que escolhe aleatoriamente uma semana para começar a manutenção dentro da janela de oportunidade e está perto da data de parada ideal, considerando o modelo de informação perfeita.
Wind farms must periodically take their turbines offline in order to perform scheduled maintenance repairs. Since this interruption impacts the generation of energy and any shortfall in production must be covered by energy purchases in the spot market, determining the optimal time to start maintenance work at a wind farm is key to maximizing your revenue, which is a function of both the expected wind speeds and electricity spot prices. In this study we develop a model to determine the optimal maintenance schedule in a wind farm. We analyze a window of opportunity in the most likely period of the year and perform weekly updates of expected wind speeds and energy price forecasts. Wind speeds are forecasted with an ARIMA model, while spot prices are simulated under the Newave dual stochastic programing model. The decision to defer maintenance to a future date is modeled as an American real option. We test two models with actual data from a wind farm in the Brazilian Northeast, and compare our results with current practice and with maintenance scheduling considering perfect information in order to determine the benefits of the model. The results suggest that the models may provide significant advantages over a stopping decision that randomly chooses a week to begin maintenance within the opportunity window and is close to the ideal optimal stopping date considering perfect model.

This report evaluate the maintenance policies that been applied within specific industrial company, Taken into considerations all corrective and preventive maintenance costs ,in addition to optimise best preventive maintenance schedule for minimum cost. Dynamate Intralog AB was the surveyed company that been encountered high maintenance cost compatible with less productivity, therefore obtaining maintenance schedule policy for minimum cost was the best solution for their problem, then by calculating their corrective and preventive maintenance cost the optimum time was acquired. Finally, the maintenance schedule approve that organized maintenance based on optimum time enhance the productivity and minimize the company maintenance cost.

Air transportation offers both passenger and freight services that are essential for economic growth and development. In a highly competitive environment, airline companies have to control their operating costs by managing their flights, aircraft, and crews effectively. This motivates the extensive use of analytical techniques to solve complex problems related to airline operations planning, which includes schedule design, fleet assignment, aircraft routing, and crew scheduling. The initial problem addressed by airlines is that of schedule design, whereby a set of flights having specific origin and destination cities as well as departure and arrival times is determined. Then, a fleet assignment problem is solved to assign an aircraft type to each flight so as to maximize anticipated profits. This enables a decomposition of subsequent problems according to the different aircraft types belonging to a common family, for each of which an aircraft routing problem and a crew scheduling or pairing problem are solved. Here, in the aircraft routing problem, a flight sequence or route is built for each individual aircraft so as to cover each flight exactly once at a minimum cost while satisfying maintenance requirements. Finally, in the crew scheduling or pairing optimization problem, a minimum cost set of crew rotations or pairings is constructed such that every flight is assigned a qualified crew and that work rules and collective agreements are satisfied. In practice, most airline companies solve these problems in a sequential manner to plan their operations, although recently, an increasing effort is being made to develop novel approaches for integrating some of the airline operations planning problems while retaining tractability. This dissertation formulates and analyzes three different models, each of which examines a composition of certain pertinent airline operational planning problems. A comprehensive fourth model is also proposed, but is relegated for future research. In the first model, we integrate fleet assignment and schedule design by simultaneously considering optional flight legs to select along with the assignment of aircraft types to all scheduled legs. In addition, we consider itinerary-based demands pertaining to multiple fare-classes. A polyhedral analysis of the proposed mixed-integer programming model is used to derive several classes of valid inequalities for tightening its representation. Solution approaches are developed by applying Benders decomposition method to the resulting lifted model, and computational experiments are conducted using real data obtained from a major U.S. airline (United Airlines) to demonstrate the efficacy of the proposed procedures as well as the benefits of integration. A comparison of the experimental results obtained for the basic integrated model and for its different enhanced representations reveals that the best modeling strategy among those tested is the one that utilizes a variety of five types of valid inequalities for moderately sized problems, and further implements a Benders decomposition approach for relatively larger problems. In addition, when a heuristic sequential fixing step is incorporated within the algorithm for even larger sized problems, the computational results demonstrate a less than 2% deterioration in solution quality, while reducing the effort by about 21%. We also performed an experiment to assess the impact of integration by comparing the proposed integrated model with a sequential implementation in which the schedule design is implemented separately before the fleet assignment stage based on two alternative profit maximizing submodels. The results obtained demonstrate a clear advantage of utilizing the integrated model, yielding an 11.4% and 5.5% increase in profits in comparison with using the latter two sequential models, which translates to an increase in annual profits by about $28.3 million and $13.7 million, respectively. The second proposed model augments the first model with additional features such as flexible flight times (i.e., departure time-windows), schedule balance, and demand recapture considerations. Optional flight legs are incorporated to facilitate the construction of a profitable schedule by optimally selecting among such alternatives in concert with assigning the available aircraft fleet to all the scheduled legs. Moreover, network effects and realistic demand patterns are effectively represented by examining itinerary-based demands as well as multiple fare-classes. Allowing flexibility on the departure times of scheduled flight legs within the framework of an integrated model increases connection opportunities for passengers, hence yielding robust schedules while saving fleet assignment costs. A provision is also made for airlines to capture an adequate market share by balancing flight schedules throughout the day. Furthermore, demand recapture considerations are modeled to more realistically represent revenue realizations. For this proposed mixed-integer programming model, which integrates the schedule design and fleet assignment processes while considering flexible flight times, schedule balance, and recapture issues, along with optional legs, itinerary-based demands, and multiple fare-classes, we perform a polyhedral analysis and utilize the Reformulation-Linearization Technique in concert with suitable separation routines to generate valid inequalities for tightening the model representation. Effective solution approaches are designed by applying Benders decomposition method to the resulting tightened model, and computational results are presented to demonstrate the efficacy of the proposed procedures. Using real data obtained from United Airlines, when flight times were permitted to shift by up to 10 minutes, the estimated increase in profits was about $14.9M/year over the baseline case where only original flight legs were used. Also, the computational results indicated a 1.52% and 0.49% increase in profits, respectively, over the baseline case, while considering two levels of schedule balance restrictions, which can evidently also enhance market shares. In addition, we measured the effect of recaptured demand with respect to the parameter that penalizes switches in itineraries. Using values of the parameter that reflect 1, 50, 100, or 200 dollars per switched passenger, this yielded increases in recaptured demand that induced additional profits of 2.10%, 2.09%, 2.02%, and 1.92%, respectively, over the baseline case. Overall, the results obtained from the two schedule balance variants of the proposed integrated model that accommodate all the features of flight retiming, schedule balance, and demand recapture simultaneously, demonstrated a clear advantage by way of $35.1 and $31.8 million increases in annual profits, respectively, over the baseline case in which none of these additional features is considered. In the third model, we integrate the schedule design, fleet assignment, and aircraft maintenance routing decisions, while considering optional legs, itinerary-based demands, flexible flight retimings, recapture, and multiple fare-classes. Instead of utilizing the traditional time-space network (TSN), we formulate this model based on a flight network (FN) that provides greater flexibility in accommodating integrated operational considerations. In order to consider through-flights (i.e., a sequence of flight legs served by the same aircraft), we append a set of constraints that matches aircraft assignments on certain inbound legs into a station with that on appropriate outbound legs at the same station. Through-flights can generate greater revenue because passengers are willing to pay a premium for not having to change aircraft on connecting flights, thereby reducing the possibility of delays and missed baggage. In order to tighten the model representation and reduce its complexity, we apply the Reformulation-Linearization Technique (RLT) and also generate other classes of valid inequalities. In addition, since the model possesses many equivalent feasible solutions that can be obtained by simply reindexing the aircraft of the same type that depart from the same station, we introduce a set of suitable hierarchical symmetry-breaking constraints to enhance the model solvability by distinguishing among aircraft of the same type. For the resulting large-scale augmented model formulation, we design a Benders decomposition-based solution methodology and present extensive computational results to demonstrate the efficacy of the proposed approach. We explored four different algorithmic variants, among which the best performing procedure (Algorithm A1) adopted two sequential levels of Benders partitioning method. We then applied Algorithm A1 to perform several experiments to study the effects of different modeling features and algorithmic strategies. A summary of the results obtained is as follows. First, the case that accommodated both mandatory and optional through-flight leg pairs in the model based on their relative effects on demands and enhanced revenues achieved the most profitable strategy, with an estimated increase in expected annual profits of $2.4 million over the baseline case. Second, utilizing symmetry-breaking constraints in concert with compatible objective perturbation terms greatly enhanced problem solvability and thus promoted the detection of improved solutions, resulting in a $5.8 million increase in estimated annual profits over the baseline case. Third, in the experiment that considers recapture of spilled demand from primary itineraries to other compatible itineraries, the different penalty parameter values (100, 50, and 1 dollars per re-routed passenger) induced average respective proportions of 3.2%, 3.4%, and 3.7% in recaptured demand, resulting in additional estimated annual profits of $3.7 million, $3.8 million, and $4.0 million over the baseline case. Finally, incorporating the proposed valid inequalities within the model to tighten its representation helped reduce the computational effort by 11% on average, while achieving better solutions that yielded on average an increase in estimated annual profits of $1.4 million. In closing, we propose a fourth more comprehensive model in which the crew scheduling problem is additionally integrated with fleet assignment and aircraft routing. This integration is important for airlines because crew costs are the second largest component of airline operating expenses (after fuel costs), and the assignment and routing of aircraft plus the assignment of crews are two closely interacting components of the planning process. Since crews are qualified to typically serve a single aircraft family that is comprised of aircraft types having a common cockpit configuration and crew rating, the aircraft fleeting and routing decisions significantly impact the ensuing assignment of cockpit crews to flights. Therefore it is worthwhile to investigate new models and solution approaches for the integrated fleeting, aircraft routing, and crew scheduling problem, where all of these important inter-dependent processes are handled simultaneously, and where the model can directly accommodate various work rules such as imposing a specified minimum and maximum number of flying hours for crews on any given pairing, and a minimum number of departures at a given crew base for each fleet group. However, given that the crew scheduling problem itself is highly complex because of the restrictive work rules that must be heeded while constructing viable duties and pairings, the formulated integrated model would require further manipulation and enhancements along with the design of sophisticated algorithms to render it solvable. We therefore recommend this study for future research, and we hope that the modeling, analysis, and algorithmic development and implementation work performed in this dissertation will lend methodological insights into achieving further advances along these lines.
Ph. D.

In the experimental ITER fusion reactor, currently under construction in Cadarache, France, components close to the plasma will get activated and contaminated over time. Therefore, these components will need to be maintained remotely in a so called hot cell facility. The maintenance will be executed according to step-by-step procedures, with every procedure meticulously validated and formally described in an Operation Sequence Description (OSD). To support formal validation, OSDs are to be captured in an ITER-dedicated Structured Language (SL), a form of domain specific programming language. The Remote Handling Study Centre (RHSC), located at FOM institute DIFFER, Nieuwegein, The Netherlands, has an ITER Remote Handling Control Room representative setup which connects to a virtual ITER Hot Cell back-end environment. In this setup, Remote Handling maintenance scenarios and procedures can be tested under realistic conditions. In this thesis, a Structured Language for ITER maintenance is proposed, implemented as a prototype to capture several realistic operational sequences from existing projects, and integrated in the RHSC workflow. The Structured Language programs are converted to schedulable tasks, by inferring their resource usage and time duration from the structured task descriptions. These tasks are then scheduled using a proposed set of scheduling heuristics. The resulting schedule is subsequently submitted to many simulated executions, with random variation in the execution time of individual tasks. The variation that is applied in the execution time, is based on representative task execution times was measured for a recent and repetitive set of maintenance tasks performed at JET. It is shown that inserting a certain amount of slack in the schedule improves its robustness. ITER maintenance scheduling should account for uncertainty by including slack in the resulting planning.

In this thesis the maintenance scheduling optimization problem of a multi-component system is formulated as a multi-objective stochastic dynamic problem, which is solved by first transforming the multi-objective formulation into a single-objective one via the weighted-sum method, and then using an iterated two-stage stochastic linear programming approach to solve the stochastic problem. The main application is the maintenance of a commercial gas turbine aero-engine. The model determines optimal opportunistic replacement schedules considering both deterministic and stochastic engine configurations. The proposed methodology provides maintenance planners with a decision tool that simultaneously minimizes the expected total cost of providing the maintenance service, and the expected total number of service interruptions due to maintenance during a finite horizon. The analysis presented in this thesis considers the indentured configuration of a modular aero-engine and investigates the sensitivity of the solutions to variations in a number of critical parameters.

This thesis analyzes the requirements of the dance school on the software produced and designs all layers required for implementation of this product. The product manages courses, their attendees, lectors, places where the courses are held and related financial operations. It also includes an interface for automatical generation of schedules for courses according to the preferences of the dance school and course attendees. This thesis also includes detailed model of database structure, object layer model, user interface designs and describes their implementation. Furthermore this thesis includes description of communication between all parties participating in created solution and feedback from users.

Cette thèse étudie le problème de planification de vol et de la maintenancedes avions militaires. D’abord, nous étudions la complexité de ce problème d’optimisation.Puis, nous proposons un modèle de programmation linéaire en nombres entiers (PLNE) pourle résoudre. Nous construisons un générateur d’instances et une heuristique pour générer dessolutions initiales. Ensuite, nous appliquons l’Apprentissage Automatique pour améliorer laperformance des modèles PLNE en utilisant des coupes valides générées à partir des conditionsinitiales et des coupes apprises à partir de la prédiction des caractéristiques de solutionsoptimales. Ces coupes sont appliquées à un nouveau modèle PLNE. Le résultat est une réductiondu temps de résolution avec peu de pertes d’optimalité et de faisabilité par rapport auxméthodes matheuristiques alternatives. Finalement, nous présentons une nouvelle matheuristiquepour résoudre efficacement des grandes instances. La méthode utilise une descente àvoisinage variable qui combine la programmation dynamique (DP) et l’horizon glissant. LaDP exploite une représentation en graphe de l’espace des solutions de chaque avion. Le résultatest des solutions rapides et presque optimales, et un passage à l’échelle efficace pourdes instances de très grande taille
This thesis studies the long term Military Flight and Maintenance Planningproblem. First, we evaluate the complexity of this optimisation problem. Then we propose aMixed Integer Programming (MIP) model to solve it. We develop an instance generator anda heuristic to generate initial solutions. Furthermore, we apply Machine Learning to improvethe performance of the MIP model by using valid cuts generated on the basis of initialconditions and learned cuts based on the prediction of characteristics of optimal solutions.These cuts are applied to a new MIP model. This results in reductions in the solutiontime with little losses in optimality and feasibility in comparison to alternative matheuristicmethods. Finally, we present a new matheuristic to efficiently solve large instances. Themethod employs a Variable Neighborhood Descent that combines Dynamic Programming(DP) and Rolling Horizon neighborhoods. The DP is applied to a graph representation of thesolution space for a single aircraft. This results in fast good quality solutions and an efficientscaling for very large instances

The aim of my thesis is the Construction technological project of nursery school building. The work involves technical report building equipment, technological instruction for selected activities, inspection and test plans, design of mechanical assemblies, transport links, schedule of health and safety, as well as environmental protection, itemized project budget, timetable and building maintenance instructions

Study 1 evaluated the use of a behavioral skills training package (BST) to teach three adults with autism spectrum disorders job interview and conversation skills. Participants were asked to have a mock job interview and conversation with the researcher. Participants' behavior was scored according to the conversation and job interview task analyses. The BST package included instruction, modeling, rehearsal, feedback, and reinforcement. A dense or lean schedule of reinforcement was assigned to each social skill based on performance during baseline. Social skills increased for all three participants when the BST package was implemented. Study 2 evaluated if dense or lean schedules of reinforcement affect maintenance of social skills. Two participants from Study 1 participated. Participants' BST data from Study 1 was used as baseline, followed by a maintenance phase. During this phase no instruction, modeling, rehearsal, feedback, or reinforcement was provided. The effect of rate of reinforcement during baseline on maintenance was evaluated.

The thesis concerns the construction of an apartment building in Velke Mezirici. The project describes construction and engineering solutions of the building itself. It consists of the technical report, the financial proposal, the construction site drawings, the building schedule, the supervisory and testing procedures, technological standards (thermal insulation and roof assembly), construction machinery, BOZP, fire safety regulations and construction maintenance.

This thesis deals with constructive -technological solutions of construction of two residential buildings A and B in Uničov. The thesis includes preparation and construction site equipment, technological prescription for implementation of anhydrite floors, time schedule and financial plan of construction, project budget, monitoring and test plans, instructions for maintenance, fire problem solution and security plan for requirements of the EMS.

Master’s thesis is concerned with maintenance management in manufacturing companies focusing on TPM. The first part of the thesis deals with the topic theoretically and proposes possible solution in company Siemens Electric Machines s.r.o. based on system analysis. The practical part then describes the current state of maintenance management and recommend various measures to improve autonomous, scheduled and reactive maintenance in this company.

This project is part of a collaborative MSc training programme between the Aviation Industries of China (AVIC) and Cranfield University, aiming at enhancing the competitiveness of AVIC in both international and domestic aviation market through applying continuing airworthiness policies in the whole aircraft development process. The arrangement of the research project is that all students start with a Group Design Project which is based on the Flying Crane Project provided by AVIC. Individual research projects will address some aspects of the Flying Crane Project during the Group Design Project, and then further developed during the period for individual projects. The aim of this research is to apply the airworthiness requirements and the methodology of the Maintenance Steering Group logic (MSG-3) in the Flying Crane Project. This is because that maintenance is one of the key factors of Continuing Airworthiness, and MSG-3 logic is the most accepted and approved method to develop scheduled maintenance for civil aircrafts. The main objectives of this project include: (1) To investigate current Continuing Airworthiness regulations, including European airworthiness requirements (as the main regulation to comply with) and Chinese airworthiness regulations (as an important reference and supplement to the research); (2) To investigate the main analysis methodology of reliability and maintainability, including Damage Tolerance and Failure Mode and Effect Analysis (FMEA); (3) To analyse the data resulted from the Group Design Project using MSG-3 logic to produce a set of Continuing Airworthiness instructions, for the operator and maintenance organisation of the aircraft, from the design organization’s perspective; (4) To develop Continuing Airworthiness instructions for airline operators to compose maintenance programmes for Flying Crane aircrafts, including maintenance tasks and intervals for the selected airframe systems and structural components; and (5) To identify applicable maintenance organisations in China for Flying Crane aircrafts in accordance with both European and Chinese airworthiness requirements. On completion of this research, two aspects of Continuing Airworthiness have been investigated, including maintenance programme and maintenance organization. With MSG-3 logic, the author developed the maintenance plan for three structural components (fuselage skin panel, wing root joint, and fin-fuselage attachment) and one airframe system (fuel system) based on results from the Group Design Project. The author also investigated the Chinese domestic aircraft maintenance companies, and selected suitable maintenance organizations based on technical and economical criteria.

The research topic is: Tools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles. This research has specific reference to the SASOL Prillan plant based in SASOL, Sasolburg. The purpose of this research is to identify tools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles. These tools must be aimed to increase the proactive work capacity index, Figure 3, and to identify and/or develop tools that can be used by the engineering team of this explosives manufacturing plant to increase equipment reliability and performance. In this research assets include people. The meaning and application of asset management principles were researched and the tools needed to combine existing efforts and future needs are discussed. The human element to ensure the successful implementation of an asset management culture was researched and attributes of leaders and a change model is presented. This research was done into the wider engineering management discipline and not only maintenance. The method used to gather data was by means of interviews of a sample group within this organization. As this manufacturing unit makes use of subject matter experts, these support functions and plant personnel that were not interviewed, were issued with questionnaires to ensure that the sample group is a fair representation of the total manufacturing facility. To obtain a holistic view of potential shortcomings within the current maintenance strategy, all disciplines and levels within this operation were interviewed and commonalities of various asset management models were determined and used to define existing problem areas. This data was used to determine statistical correlations. The case study presented in Chapter 1 indicates that there is a case for change that can improve the proactive work capacity index of the engineering team. The results of this research confirm that there is in fact a real requirement to increase spares accuracy, improve on technical training as well as a need to establish visual performance indicators (dashboard) to measure overall equipment efficiency with the goal toTools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles increase equipment reliability and performance. The technical training referred to in this research reflects on training of people on equipment after investment in new technology. The current spares holding strategy is lacking equipment description accuracy. Furthermore, it is recommended that the implementation of career paths and development plans for individuals must be developed to create an environment of learning. The use of user status information captured on the computerized maintenance management system (SAP R/3) can add to the management of works orders and indicate where the focus must be to complete overdue work orders. Open work orders should be used to manage expenditure, to measure planning efficiency and to manage the cash flow of the business. The use of overall equipment efficiency and engineering efficiency measures is recommended and must be visually displayed on a “dashboard”. It was recommended that the engineering and operations personnel of this manufacturing plant be trained in asset management principles and that balanced scorecards are developed to ensure that the strategies of the various departments are aligned with the business strategy. Diagram 1 best illustrates the thinking and process flow of this research. The flow diagram shows five distinct stages and the appropriate objectives and/ or elements that were considered. The dissertation is also structured in this manner. All abbreviations, acronyms and definitions used in this document were listed in APPENDIX B
Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

碩士
國立臺北教育大學
資訊科學系碩士班
98
This study develops mathematical models for generator unit maintenance scheduling problem, its Objective Functions, and constraints of consideration. This paper introduces the theoretical basis of Immune Algorithm (IA) and how to encode and perform calculation with examples. This paper introduces the application of Heuristics, Successive Approximation Dynamic Programming (SADP), and IA to solve the generator unit maintenance scheduling problem. IA is performed using the initial solution obtained by the Heuristics method based on the data of all the generator units and their loads. The proposed method is applied to solve the maintenance scheduling problem of a simple unit system. The IA method is applied on the Tai Power system, and the results are compared with the traditional SADP. The simulation and testing results demonstrate that IA can effectively solve the generator unit maintenance scheduling problem.

博士
國立中央大學
土木工程學系
101
In this dissertation, on the basis of the carrier’s perspective, we try to develop two optimization models for annual schedule adjustments, in accordance with the objective and related constraints required in actual operations. This dissertation is divided into two essays. In the first we study annual long-term schedule adjustments model for aircraft maintenance by deterministic planning with the prevention to deal with the impact from latent stochastic disturbances in actual operations. The model is formulated as a zero-one integer program which is solved using the mathematical programming solver, CPLEX. In addition, a simulation-based evaluation method is also developed for evaluating the schedules obtained from deterministic model of the first essay and the representative traditional deterministic model in simulated real operations. In the second we consider framework of the first essay to develop an optimization model for annual schedule adjustments under stochastic aircraft check-in and maintenance times in actual operations. To effectively solve the model with realistically large problems occurring in real world, a heuristic is developed with the use of the mathematical programming solver, CPLEX. In addition, a simulation-based evaluation method is also developed for evaluating the schedules obtained from the stochastic and deterministic models in simulated real operations. Finally, to demonstrate and to evaluate the two models in practice, we individually perform a case study using the real operating data from a major aircraft maintenance center in Taiwan. The test results are good, showing that deterministic model of the first essay is better than the traditional deterministic model and the stochastic model of the second essay is the best of the three models. It is also showing that the two models would be robust and useful planning tools for aircraft maintenance centers to effectively adjust their aircraft maintenance schedules annually under stochastic aircraft check-in and maintenance times in actual operations.

碩士
國立中央大學
土木工程學系在職專班
107
The operation of Massive Transit System (MRT) covered related facilities such as construction, vehicle and environment, etc. In addition to the core equipment of electrical and mechanical systems, there were still lots of non-core equipment that were serving the passengers, and these non-core equipment were compatible with generic system in the private sector, therefore, the maintenance job of these non-core system can be appropriately considered, after the operation was stable, to be outsourced to professional service supliers. Meanwhile, the business operation department of the MRT can apply the maintenance budget more efficiently and focus on the electrical and mechanical part of the vehicle track. In this study, focuses were put on the maintenance job for elevator and escalator and time and labor cost spent on maintenance in MRT system. Meanwhile, linear integer programming optimization model was used, after considering the maintenance time for periodical maintenance based on each station’s characteristic, the optimized maintenance scheduling and cost need were studied. In order to verify the reasonability and practicality of this model, the elevator and escalator of MRT station in airport was used as example for simulation; meanwhile, the labor cost of scheduling obtained using the constructed LINGO solution-finding model was compared to that of scheduling based on human experience, the result was used to verify that the scheduling generated by the optimization model of this study can indeed save more cost as compaed to the scheduling based on human experience. This study is applicable to the maintenance scheduling programming and maintenance cost related issues of MRT equipment, hopefully, the result can be used as basis by the decision maker for labor outsourcing expense, or as reference for manpower arrangement by itself.

碩士
國立臺灣科技大學
營建工程系
105
For the past few years, Taiwanese manufacturing industry with advanced mechanical equipment replaced the labor-intensive process. The use of industrial equipment is increasing, which impact also the importance of the maintenance standard process. The "Breakdown Maintenance" is used as a traditional equipment maintenance standard, which consist to intensify the maintenance process when abnormal situation incurred. This practice is compared as a human body when no prior prevention was set up, the occurrence of the situation will often result to more and bigger problems, and finally conclude into a higher cost in total expense. With the improvement of relevant management knowledge in recent years, the equipment maintenance process of has gradually adopted the concept of "preventive maintenance" to regularly maintain, record and refer the equipment system, in order to correct the maintenance cycle to effectively extend the equipment function by prevent early malfunction. Even if the factory management staff have such concept, however, the practical operation will still be due to the traditional scheduling process, when the demand for manpower is too large or low, resulting in lack of resources caused by mismanagement of schedule, and finally returned to the passive maintenance of the situation. Thus, this research includes a process of equipment maintenance schedule of a flour factory as an example, in accordance with the factory equipment maintenance cycle and required maintenance time. The implementation of two different optimization programs was used to find the best scheduling time, and calculate the average daily demand of human labor, in order to stabilize the productivity according to the situation. Managers can accurately grasp the deployment of human resources, by applying this method to reduce the labor cost. To verify the result of this case study, the scheduling result of the flour factory will be compared with its original manpower scheduling model. Once completed, the best solution will be chosen depending on the result of each optimization program and confirmed by the desired results, then put in practical use. If some parameters are adjusted, it can also be applied to the implementation of construction equipment maintenance schedule or other area. Therefore, it can help also decision-makers to avoid unnecessary waste of manpower, unexpected equipment failure and prevent maintenance expenditure.

This MS thesis studies the effect of uncertainty in the demand of finished products, supply of raw materials, and maintenance resources availability on the maintenance schedule of a manufacturing facility. A simulation model is formulated in order to realistically model manufacturing systems of various complexities, consisting of multiple interacting machines that degrade and fail over time, and are repaired using imperfectly available maintenance crews and resources. A design of experiments (DOE) based sensitivity study is conducted to find the system parameters that mostly affected the maintenance decisions and corresponding profits.
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碩士
國防大學理工學院
兵器系統工程碩士班
101
The annual repair task for military base level mainly relies on the maintenance scheduling program which affects the maintenance performance. In recent years, the military organization has been streamlined largely to make implementation of military task more efficient. Furthermore, an excellent maintenance schedule can avoid unnecessary wastes of human resources and efficiently support requirements of military drills, and thereby enhance the warfare force. This thesis simulates the scenario regarding the maintenance of aircraft engine accessories to establish a “hybrid flow shop maintenance scheduling model with machine availability constraints consideration”. An improved particle swarm optimization (IPSO) is proposed to optimize the established maintenance model. The ISPO proposed consists of two stages. The first stage mainly adopts the idea of linear time-varying approach in which the values of search parameters of IPSO are varied with the increment of iterations instead of constant setting for conventional PSO to improve the ability of particles to explore the entire solutions area. The second stage utilizes the variable neighborhood search (VNS) approach to search intensively the area around the best solutions obtained from the first stage in hope to further the solutions efficacy. The parameters settings of time-varying approach are determined via response surface methodology instead of trial-and-error method. The well-known benchmark problems for static hybrid flow shop verify the effectiveness of the proposed approach. Finally, the proposed approach is employed to optimize a real case of maintenance schedule of aircraft engine accessories to extend the practicality of this thesis.

碩士
東海大學
工業工程與經營資訊學系
106
In the context of the rapid advancement of global technology and electronic products, Artificial Intelligence (AI) and Big Data have gradually turned to be commercialized. Semiconductor technology has become one of the most important technologies in this era and Taiwan ranked as the top three in the semiconductor industry of the world. Reducing manufacturing cost and increasing the production capacity are crucial for any semiconductor company due to the vast facility investment. Taking semiconductor plant in Taiwan for example, the throughput will be significantly affected by unexpected machine breakdown and scheduled maintenance, the right timing for scheduling machine maintenance is critical for ensuring production quality and reducing machine breakdown. Consequently, this research applies the decision tree as the predictive model for the machine breakdown combined with simulation system for generating an effective maintenance schedule based on the historical production data. In the past, the factory usually adopted the predetermined fixed-quantity maintenance approaches such as time-based maintenance (TBM) and predictive maintenance of capacity (PMC). On the contrary, this study employed the decision tree and capacity planning simulation (CPS) to develop a maintenance schedule decision support model (MSDSM), which will integrate with ERP and MES, to dynamically generate an effective maintenance schedule. The maintenance decision tree obtained from MSDSM was evaluated by varying production quantity, maintenance time horizon and the machine numbers, results show that the prediction accuracy of machine breakdown can reach up to 60%. The MSDSM is also applied in a full-scale 12” semiconductor wafer fab, the maintenance schedule generated from MSDSM will result in a lower machine breakdown rate 43% and higher throughput compared to the original production data.

碩士
國防大學理工學院
兵器系統工程碩士班
100
The main task of combined logistics automotive base depot in military is implementation of maintenance for wheel vehicles. The determination of maintenance schedule heavily relies on the managers’ experience which is rather inefficient and results in waste of human resources, still has large room for improvement. Therefore, this thesis considers the maintenance property belonging to the flow shop process to establish a bi-objective maintenance scheduling model in which makespan and total flow time are minimized simultaneously. The maintenance capacity of combined logistics automotive base depot is hopefully improved. In order to efficiently optimize the model established, a multi-objective genetic algorithm (MOGA) incorporating the idea behind Pareto optimization is proposed. Several distinct maintenance alternatives can be obtained after resolving the bi-objective maintenance scheduling model. Accordingly, the manager can determine the most appropriate maintenance alternative with consideration of task requirements and limitations of human resources. Furthermore, this thesis utilizes the international benchmark problems form website to demonstrate the efficacy of the proposed MOGA. Finally, the proposed approach is applied to resolve a real case from combined logistics automotive base depot in military and thereby extend the practicability of this thesis.

碩士
國防大學理工學院
兵器系統工程碩士班
100
The annual maintenance task of base level for military solely relies on the maintenance scheduling program which affects the maintenance performance directly.This thesis simulates the scenario of arm weapons maintenance suffering from the dynamic interference of rush orders to establish a “flowshop dynamic maintenance scheduling model with learning consideration”. An improved particle swarm optimization (IPSO) is proposed to optimize the established maintenance model. The ISPO proposed consists of two stages. The first stage mainly adopts the idea of linear time-varying approach in which the values of search parameters of IPSO are varied with the increment of iterations instead of constant setting for conventional PSO to improve the ability of particles to explore the entire solutions area. The second stage utilizes the variable neighborhood search (VNS) approach to search intensively the area around the best solutions obtained from the first stage in hope to further the solutions efficacy. The parameters settings of time-varying approach are efficiently determined via response surface methodology from design of experiments instead of trial-and-error method. The well-known static flow shop benchmark problems verifies the effectiveness of the proposed approach. Finally, the proposed approach is employed to optimize the dynamic maintenance schedule of arm weapons (machine guns) to extend the practicality of this thesis.

碩士
國立東華大學
企業管理學系
93
Good maintenance, man power, and flight schedule planning are always the key elements to the good service quality, reputation and operation in commercial airlines. As a customer’s point of view, the trust of flight safety and the accuracy of flight is always leads to there satisfaction. There is been many studies on this issue over past decades, and by applying the mathematical techniques, model to help increase the flexibility of aircraft scheduling as well, but this seems to be focused on the commercial air plane more than on military air plane, and the object is tend to minimum the cost or maximum the operation profits. The research is more often to be founded from the USAir force. These techniques had been broadly used on USAir force’s annually exercise and operations to help making their decisions. For these years government is cutting the budgets for the armed force. This makes the topic “How to spend less dollar on same job.” become hot. By doing this research we are trying to develop a mathematical model to increase the flexibility of aircraft scheduling, mission assignment, but seeking the opportunities to reduce the operation cost..

碩士
義守大學
管理學院管理碩士在職專班
101
The situation and environment between Taiwan Strait are different from those of other countries. Cross-strait combat readiness is urgent and cannot be delayed, resulting in a high frequency use of its military aircraft. The range of combat readiness is also extended due to different exercises, training, and operation mission. The frequency and variance of maintenance and repair for military aircraft are relatively huge compare to those of civil aircraft. In the stage of plant maintenance, operation time is highly uncertain and the requirement of maintenance resources constantly varies. With the demand of military readiness and the requirement of proper rate policy, whether the plant can complete the maintenance and repair job and delivery the aircraft to military unit on time is an important question worth to investigate. Using Program Evaluation and Review Technique (PERT), this study focuses on the items that are important or prone to mistakes in the planned maintenance and repair process. To identify the critical path jobs in the factory maintenance and repair process, to assess its operating time, and to evaluate if the practice jobs in the project schedule is appropriate. Finally, suggestions for improving the accuracy and the arrangement of the project schedule are provided.

碩士
國立東華大學
企業管理學系
94
Nowadays, “Fleet Management”becomes a hot issue in avionics business. The most successful commercial airline companies always find a way to run their business more efficiently, and they are not only work on reducing the total operation cost but also find a way to improve competition ability. Fleet assignment and maintenance scheduling are two most predictable factors that will affect on fleet management (on both commercial and military aircraft). Anyone who pays attention on improving one of these two things will also improving their competition as well. The mixed-integer (0, 1, and integer) linear programming algorithm is used in this research to help develop a time-space network model to solve the fleet assignment and maintenance scheduling problem. And by using latest computer technology can also make the fleet Management task even more efficiently and accurate.

碩士
國立成功大學
交通管理學系
89
Temporary aircraft dispatching problem is to dispatch the available aircraft to serve the scheduled flights in the best way while certain aircraft is/are not available for the originally assigned flights due to unexpected incidents. The importance of such a problem increases as the cost of aircraft on ground increases. However, it becomes more and more complicated and cannot be solved efficiently and effectively for airlines as the fleet grows to some extent. This research formulates such a problem while taking in account the network characteristics of the flag carrier of Taiwan, and try to apply the concept of time-aircraft network to solve it. The most important is that the problem studied in this research will consider the maintenance constraints and aircraft utilization in between two scheduled maintenance checks. In fact, the Civil Aviation Authority has very strict regulations regarding aircraft maintenance. All the maintenance requirements are very important factors for aircraft dispatching since they involve airworthiness. The maintenance requirements considered in this research include the maximum flight time between two A-checks, the required ground time for each A-check, the hangar capacity and the available maintenance labor. The objective function is the minimum aircraft dispatching cost and the time loss cost in between two A-checks. We solve this model by combining Branch & Bound algorithm and parameters adjusted. In the model application, this model help to dell with temporary aircraft dispatching problem, to reschedule the Aircraft dispatching problem according to company requirements, to bring up the different suggests when the certain aircraft unavailable.

碩士
國立臺北教育大學
資訊科學系碩士班
106
With the rapid development of information technology, information technology can be applied more and more widely. For example, in the financial industry, the medical industry, the logistics industry, and the semiconductor industry, all industries have applied information technology to enhance their competitive advantage. With modern people paying more attention to oral health, the application of information technology in oral health management is very common. People pay more and more attention to the problem of oral diseases. Even if oral diseases are not an infectious disease, about 15-20% of adults aged 35 to 44 worldwide suffer from serious oral diseases. Oral health is a very important and important factor in the quality of personal life. If one's oral health is poor, it will inevitably affect the quality of life of this person. At present, the oral care system that combines information technology and big data is not yet mature. Therefore, it is very important to develop an oral treatment and care system that combines information technology. This way, the hospital can make a patient’s oral health. Comprehensive monitoring and care to provide better medical quality. Based on the situation model, this study analyzes the five aspects of oral health risk, risk management, information technology monitoring, management, and management performance. It collects user data through questionnaire surveys and uses statistical methods based on the results of the questionnaire. Analysis to discuss the impact of IT monitoring on management performance.

碩士
國防大學理工學院
兵器系統工程碩士班
102
The military organization has been streamlined substanitally to make implementation of military task more efficient in recent years. Furthermore, an excellent maintenance schedule can avoid unnecessary wastes of human resources to efficiently support requirements of military drills and thereby enhance the warfare force. This thesis simulates the scenario regarding the maintenance of armored vehicle engines accessories to establish a dynamic maintenance scheduling model for the flexible flowshop. Besides the transportation times of each maintenane part duing maintenance procedure, the dependence between the setup time and parts maintenance order is also accounted for in the established model in oorder to precisely reflect the actual maintenance situation. This thesis also considers the impact of unanticipated rush orders to mainteance schedule determined to propose a reoptimizing approach. A hybrid particle swarm optimization (HPSO) algorithm combining variables neighborhood search (VNS) method is proposed to efficiently optimize the established mathematical model. The parameters settings related to the proposed HPSO algorithm are determined via response surface methodology instead of conventional trial-and-error method. The effectiviness of the proposed HPSO algorithm is verified by comparing with four improved PSO algorithm using randomized complete block design. Finally, the proposed approach is employed to optimize the dynamic maintenance schedule of armored vehicle engines accessories to extend the practicality of this thesis.

Problem statement: Manufacturing and production plants operate machines and equipment that deteriorate with usage and time thus requiring maintenance actions to restore them back to their original operational conditions. Approach: This study investigates the current standard of maintenance planning at a steel manufacturing facility in South Africa. The study begins with a thorough literature study to find good characteristics of planning which should be present at any facility that is optimally engaged in performing excellent maintenance planning effectively and efficiently. A number of key observations from the literature are made indicating that planning is a key component of maintenance and affects excellence in maintenance significantly. The literature recommends that planning should be set and based on key principles to allow for standardisation and efficiency. An empirical study in the form of a survey is then completed to benchmark the current maintenance-planning environment of the steel facility against the good characteristics of maintenance planning found in literature. Results: The results from the empirical study show that the current maintenance environment at the steel manufacturer is not optimal. The following issues are uncovered from the study: no schedulers employed to relieve the planners’ work overload, no guiding principles for planning and standardisation of work planning, no efficient shutdown planning and also no existent measures for tracking some of the key performance areas. Conclusion: Key recommendations to be considered for implementation for improving the status of the maintenance environment at the works include: introducing the scheduler position, standardising planning methodologies according to specific principles and rigorously focusing on overall maintenance improvement using standardised methodologies.
MBA (Business Administration), North-West University, Potchefstroom Campus, 2015

碩士
逢甲大學
資訊工程學系
103
Multi-core system has become ubiquitous on nowadays computing architecture, the advantage of multi-core system is tasks can be assigned to many cores to execute and then improve efficiency, but it also results in shared resource contention, such as last level cache(LLC), memory and bandwidth. With advances in semiconductor process, due to the number of cores and their multithreading capabilities increase, the contention for the shared resource is becoming a major concern. Therefore, many related researches proposed about multi-core scheduling to improve this problem. The advantage of scheduling that does not require additional hardware can effectively improve system performance, just only modify the scheduler of the operating system, but fewer researches consider about fairness, consequently, how to design a multi-core scheduling and consider fairness has become a major research direction. In this paper, we propose a shared cache scheduling mechanism considering both shared cache contention and fairness. First of all, we quantify the busy rate of the task to the shared cache, and prove the method of selecting the task that requests for the shared cache the waiting time is shortest. We also consider the fairness and design two queue to maintain the fairness. Finally, through the algorithm we design to assign the proper task to the core. In the simulation, we compare our methods to the related researches about the performance and do the analysis.

The graduation theses at the theme ,, The optimalisation of seting land machanisation at maintenance of melioration objects (waterwork) is described using methods of scheduled maintenance of melioration objects and setting the land mechanisation at this operations with their tools. The next part of graduation theses is discribed the choose of optimal alternace (variation) resolution manner of maintenance complience with legislature and promulgation 225/2002 Sb. The general references at recultivation water reservoir (pond) is set out with practical pictures on pond Beranov near by village Čakov.

Thesis (D.Tech. - Electrical Engineering, Dept. of Process Control and Computer Systems, Faculty of Engineering and Technology)--Vaal University of Technology.
In recent years, industrial plant maintenance has changed dramatically. These changes are due to a considerable increase in the number and variety of physical plant assets, increased design complexity, new maintenance techniques and changing perspectives regarding on how to perform maintenance effectively. Managers at modern process plants are becoming increasingly aware of the extent to which equipment failure affects safety and the environment. Process plant personnel are limited in their ability to accurately and consistently evaluate the health of plant assets. Due to poor record keeping, maintenance staff often has little defence against aging equipment and asset failures. As a result companies have undertaken to implement planned equipment maintenance schedules and install new technology to allow for efficient tracking and analysing of equipment health across the board. The introduction of an integrated asset management solution is presented in this thesis. The integrated asset management solution will assist maintenance staff to cost-effectively predict the probability of asset failure prior to the occurrence of any actual plant incidents. The integrated solution documented in this thesis will be implemented at the Sasol Solvents site to enhance plant availability, maximum up time for all plant assets and plant safety. Strategic Asset Management Inc. (SAMI) uses the Operational Reliability Maturity Continuum model to improve profitability, efficiency and equipment reliability. The SAMI empirical model employs various stages to address improved performance and asset management and was used as a guideline to develop an integrated solution to optimise plant performance and profits. The integrated asset management solution, documented in this thesis, was developed with the intended function of bringing information from diverse plant based systems and field equipment to the maintenance personnel in an understandable interface so that the information can be used to improve the reliability and availability of all plant assets.

With the world economy becoming unpredictable, it has become a necessity for businesses to relook at the way they do business. The world has become competitive and companies that aim to become profitable have seen the need to find ways to improve efficiencies and increase productivity to stay relevant. There has been an adoption of strategies that are aimed at improving the efficiencies in companies such as Total Productive Maintenance (TPM). The strategy is aimed at improving equipment efficiencies and increase productivity through the transfer of certain skills from maintenance personnel to operators. The aim is that the operators perform some of the activities that the maintenance people used to do and they do the more complex tasks. By transferring these skills to operators there is constant cleaning, inspections and lubricating of equipment. This frees up time for maintenance people to do planning and other jobs that require time and higher skills levels. The implementation of these activities allows companies to tap into unused capacity that was always hidden by breakdowns and unplanned stops. The process however requires commitment from management and all stakeholders involved in the organisation. There are prescribed implementation processes that can be followed or companies can follow their own processes but the fundamentals of involving people from the onset must be followed. The involvement of stakeholders creates commitment at all levels and in order to sustain this initiative people must be committed to it. The inclusion of the activities transferred from maintenance people to operators, will reinforce the knowledge and habits required from operators and perhaps sustain the initiative.
MBA, North-West University, Potchefstroom Campus, 2015