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1
Ghodsi, Reza. "Project scheduling using simulation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0001/MQ35014.pdf.
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Ying, Chen-Tsau Chris. "Backward simulation for production scheduling purposes /." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487861396025914.
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Frantze´n, Marcus. "A real-time simulation-based optimisation environment for industrial scheduling." Thesis, De Montfort University, 2013. http://hdl.handle.net/2086/9032.
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In order to cope with the challenges in industry today, such as changes in product diversity and production volume, manufacturing companies are forced to react more flexibly and swiftly. Furthermore, in order for them to survive in an ever-changing market, they also need to be highly competitive by achieving near optimal efficiency in their operations. Production scheduling is vital to the success of manufacturing systems in industry today, because the near optimal allocation of resources is essential in remaining highly competitive. The overall aim of this study is the advancement of research in manufacturing scheduling through the exploration of more effective approaches to address complex, real-world manufacturing flow shop problems. The methodology used in the thesis is in essence a combination of systems engineering, algorithmic design and empirical experiments using real-world scenarios and data. Particularly, it proposes a new, web services-based, industrial scheduling system framework, called OPTIMISE Scheduling System (OSS), for solving real-world complex scheduling problems. OSS, as implemented on top of a generic web services-based simulation-based optimisation (SBO) platform called OPTIMISE, can support near optimal and real-time production scheduling in a distributed and parallel computing environment. Discrete-event simulation (DES) is used to represent and flexibly cope with complex scheduling problems without making unrealistic assumptions which are the major limitations of existing scheduling methods proposed in the literature. At the same time, the research has gone beyond existing studies of simulation-based scheduling applications, because the OSS has been implemented in a real-world industrial environment at an automotive manufacturer, so that qualitative evaluations and quantitative comparisons of scheduling methods and algorithms can be made with the same framework. Furthermore, in order to be able to adapt to and handle many different types of real-world scheduling problems, a new hybrid meta-heuristic scheduling algorithm that combines priority dispatching rules and genetic encoding is proposed. This combination is demonstrated to be able to handle a wider range of problems or a current scheduling problem that may change over time, due to the flexibility requirements in the real-world. The novel hybrid genetic representation has been demonstrated effective through the evaluation in the real-world scheduling problem using real-world data.
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White, David Elliot. "Simulation-based Optimization of Coal Barge Scheduling." NCSU, 2008. http://www.lib.ncsu.edu/theses/available/etd-01082008-080147/.
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In an attempt to improve the process of supplying coal by way of water to Progress Energyâs Crystal River power plant, a simulation-based technique was developed to find the best schedule of coal barges. The technique uses discrete event simulation principles to find the best solution based on two criteria: minimal demurrage cost and maximal coal tons moved. Many factors are taken into account including channel capacity, tide dependencies, weather delays, periods of scheduled down time, and percentage of trips to each coal terminal. The same technique is also used for long range planning in the decisions of capital allocation of equipment, barge contracts, and coal supplier contracts. A Graphical User Interface coupled with Visual Basic .Net (VB .Net) code is used to implement the approach in a user-friendly and maintainable environment.
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Deschamps, Henrick. "Scheduling of a Cyber-Physical Sytem Simulation." Thesis, Toulouse, ISAE, 2019. http://www.theses.fr/2019ESAE0024/document.
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Les travaux menés dans cette thèse de doctorat s’inscrivent dans le cadre d’un effort pluslarge d’automatisation des systèmes de simulation industriels. Dans l’industrie aéronautique,et plus particulièrement au sein d’Airbus, l’application historique de la simulation est laformation des pilotes. Il existe aussi des utilisations plus récentes dans la conception desystèmes, ainsi que dans l’intégration de ces systèmes. Ces dernières utilisations exigent untrès haut degré de représentativité, là où historiquement le plus important était le ressenti dupilote. Les systèmes sont aujourd’hui divisés en plusieurs sous-systèmes qui sont conçus, implémentéset validés indépendamment, afin de maintenir leur contrôle malgré l’augmentationde leurs complexités et la réduction des temps de mise sur le marché. Airbus maîtrise déjà lasimulation de ces sous-systèmes, ainsi que leurs intégrations en simulation. Cettemaîtriseest empirique, les spécialistes de la simulation reprennent l’ordonnancement d’intégrationsprécédentes, et l’adaptent à une nouvelle intégration. C’est un processus qui peut parfois êtrechronophage, et qui peut introduire des erreurs. Les tendances actuelles de l’industrie sont à la flexibilité des moyens de production, àl’intégration d’outils logistiques permettant le suivi, à l’utilisation d’outils de simulation enproduction, et à l’optimisation des ressources. Les produits sont de plus en plus souvent desitérations d’anciens produits améliorés, et les tests et simulations intégrés à leurs cycles de vie.Travailler de manière empirique dans une industrie qui nécessite de la flexibilité estune contrainte, et il est aujourd’hui important de facilement modifier des simulations. Laproblématique est donc de mettre en place des méthodes et outils permettant a priori degénérer des ordonnancements de simulations représentatifs.Afin de répondre à ce problème, nous avons mis en place une méthode permettant de décrireles composants d’une simulation, la manière dont cette simulation pourra être exécutée,ainsi que des fonctions permettant de générer des ordonnancements. Par la suite, nous avonsimplémenté un outil afin d’automatiser la recherche d’ordonnancement, en se basant sur desheuristiques. Enfin nous avons testé et vérifié notre méthode et outils sur des cas d’étudesacadémiques et industrielsThe work carried out in this Ph.D. thesis is part of a broader effort to automate industrialsimulation systems. In the aeronautics industry, and more especially within Airbus, thehistorical application of simulation is pilot training. There are also more recent uses in thedesign of systems, as well as in the integration of these systems. These latter applicationsrequire a very high degree of representativeness, where historically the most important factorhas been the pilot’s feeling. Systems are now divided into several subsystems that are designed, implemented andvalidated independently, in order tomaintain their control despite the increase in their complexity,and the reduction in time-to-market. Airbus already has expertise in the simulationof these subsystems, as well as their integration into a simulation. This expertise is empirical;simulation specialists use the previous integrations schedulings and adapt it to a newintegration. This is a process that can sometimes be time-consuming and can introduce errors.The current trends in the industry are towards flexible production methods, integrationof logistics tools for tracking, use of simulation tools in production, as well as resourcesoptimization. Products are increasingly iterations of older, improved products, and tests andsimulations are increasingly integrated into their life cycles. Working empirically in an industry that requires flexibility is a constraint, and nowadays itis essential to facilitate the modification of simulations. The problem is, therefore, to set upmethods and tools allowing a priori to generate representative simulation schedules.In order to solve this problem, we have developed a method to describe the elementsof a simulation, as well as how this simulation can be executed, and functions to generateschedules. Subsequently, we implemented a tool to automate the scheduling search, based onheuristics. Finally, we tested and verified our method and tools in academic and industrialcase studies
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Liu, Kuo-Ching. "Stochastic simulation-based finite capacity scheduling systems /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487946776022111.
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Matondang, Abdul Rahim. "Evaluation of real time scheduling policies using simulation." Thesis, Cranfield University, 1988. http://hdl.handle.net/1826/3704.
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The purpose of this research is to investigate the effects
of different scheduling operating policies in real- time
scheduling. The scheduling policies include due date
assignment method, priority rules, process batch method and
operator reassignment policy. A specific case of
production scheduling-in a hypothetical assembled product
manufacturing system was investigated in this research.
The simulated production system encompasses fifteen work
centres, each containing one to three identical machines
and each machine requires one operator with all operations
being perfectly efficient on all machine types. The
production -system produces finished products as well as
components and sub-assemblies. Orders from outside the
system arrive for service generated according to the
exponential distribution. The orders coming to the system
were classified into "priority" and "standard" orders.
Processing times at each work centre are statistically
independent and uniformly distributed.
A computer simulation technique was chosen as the approach
method. A computer simulation written in DBASE III PLUS
was used to generate the data for analysis. In order to
analyse the behaviour of the simulated production system
with respect to the different performance criteria, a
number of performance measures were selected. These are,
mean tardiness, percent tardy, mean work in progress, mean
machine utilisation, and mean operator utilisation.
The 2x6x2x2 complete factorial is analysed by the
analysis of variance (ANOVA) procedure to statistically
determine whether due date assignment method, priority
rules, process batch method, and operator reassignment
policy or their interaction significantly affect the performance criteria considered. Further analysis to
identify where significant differences in performance occur
is conducted via Duncan multiple comparison test.
Based upon the statistical analysis it was found that the
relative impact of due date assignment method, priority
rule, process batch method, and operator reassignment
policy or their interaction for scheduling policies in real
time scheduling to be dependent upon the measure of
performance considered. In respect of root mean square of
tardiness, the scheduling policies involving the slack time
remaining (STR) priority rule are the most important of
scheduling policies in minimising the tardiness of customer
orders produced by the company. In respect to minimising
the work in progress, there is no dominant level of due
date assignment method, or priority rule or process batch
method or operator reassignment policy. However, the
scheduling policies involving the variable process batch
(VPB) method produce the best result.
The scheduling policies involving the variable process
batch (VPB) method are the best performers in maximising
the utilisation of machine and operator.
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Cedrini, Luca. "Time Sensitive Networks: analysis, testing, scheduling and simulation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22305/.
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The industrial automation world is an extremely complex framework,
where state-of-the-art cutting edge technologies are continuously being replaced in order to achieve the best possible performances.
The criterion guiding this change has always been the productivity. This term has, however, a broad meaning and there are many ways to improve the productivity, that go beyond the simplistic products/min ratio. One concept that has been increasingly emerging in the last years is the idea of interoperability: a flexible environment, where products of different and diverse vendors can be easily integrated togheter, would increase the productivity by simplifying the design and installation of any automatic system.
Connected to this concept of interoperability is the Industrial Internet of Things (IIoT), which is one of the main sources of the industrial innovation at the moment: the idea of a huge network connecting every computer, sensor or generic device so as to allow seamless data exchange, status updates and information passing. It is in this framework that Time Sensitive Networks are placed: it is a new, work-in-progress set of communication standards whose goal is to provide a common infrastructure where all kinds of important data for an industrial automation environment, namely deterministic and non deterministic data, can flow. This work aims to be an initial step towards the actual implementation of the above-mentioned technology. The focus will therefore be not only on the theoretical aspects, but also on a set of practical tests that have been carried out in order to evaluate the performances, the required hardware and software features, advantages and drawbacks of such an application.
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Park, Seong Jae. "Bus network scheduling with genetic algorithms and simulation." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2496.
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Thesis (M.S.) -- University of Maryland, College Park, 2005.Thesis research directed by: Dept. of Civil and Environmental Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Wang, R. "Berth scheduling at seaports : meta-heuristics and simulation." Thesis, Liverpool John Moores University, 2018. http://researchonline.ljmu.ac.uk/9652/.
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This research aims to develop realistic solutions to enhance the efficiency of port operations. By conducting a comprehensive literature review on logistic problems at seaports, some important gaps have been identified for the first time. The following contributions are made in order to close some of the existing gaps. Firstly, this thesis identifies important realistic features which have not been well-studied in current academic research of berth planning. This thesis then aims to solve a discrete dynamic Berth allocation problem (BAP) while taking tidal constraints into account. As an important feature when dealing with realistic scheduling, changing tides have not been well-considered in BAPs. To the best of our knowledge, there is no existing work using meta-heuristics to tackle the BAP with multiple tides that can provide feasible solutions for all the test cases. We propose one single-point meta-heuristic and one population-based meta-heuristic. With our algorithms, we meet the following goals: (i) to minimise the cost of all vessels while staying in the port, and (ii) to schedule available berths for the arriving vessels taking into account a multi-tidal planning horizon. Comprehensive experiments are conducted in order to analyse the strengths and weaknesses of the algorithms and compare with both exact and approximate methods. Furthermore, lacking tools for examining existing algorithms for different optimisation problems and simulating real-world scenarios is identified as another gap in this study. This thesis develops a discrete-event simulation framework. The framework is able to generate test cases for different problems and provide visualisations. With this framework, contributions include assessing the performance of different algorithms for optimisation problems and benchmarking optimisation problems.
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PERES, IGOR TONA. "SIMULATION OF APPOINTMENT-SCHEDULING POLICIES IN OUTPATIENT SERVICES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=31401@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
FUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIRO
BOLSA NOTA 10
Os sistemas de agendamento de consultas tradicionalmente realizam as marcações dos pacientes em intervalos fixos de tempo, sem levar em consideração diversos fatores de complexidade do sistema de saúde. Isso pode causar mão de obra ociosa em alguns períodos do dia e longas filas de espera de pacientes em outros momentos. Nesse contexto, esta dissertação tem como intuito propor uma nova política de agendamento para uma clínica especializada em cirurgia bariátrica do Rio de Janeiro, considerando os fatores desse sistema: tempos de serviços estocásticos, impontualidade do paciente, atrasos e interrupções do serviço, e presenças de no-shows. Esta dissertação analisou diversos cenários com overbooking (marcação de pacientes adicionais), e testou as principais políticas por meio de simulação, propondo a mais adequada para a clínica. As 18 políticas de agendamento aplicadas foram encontradas através de uma extensa revisão sistemática da literatura. Com a utilização da política de agendamento OFFSET, foi possível aumentar o número de atendimentos em 30 por cento para o agendamento do principal provedor da clínica, mantendo o nível de serviço prestado. Além disto, foi proposta uma nova política de agendamento, denominada DOME CYCLE, que teve resultados superiores às demais políticas da literatura na média dos cenários realizados.
Appointment-scheduling systems traditionally schedule patient appointments at fixed intervals, without taking into account several complexity factors of health-care system. This schedule can make the server idle at certain times of the day and can produce long queues of patients at other times. In this context, the objective of this study is to propose a new scheduling policy for a clinic specialized in bariatric surgery in Rio de Janeiro, considering the following factors of this system: stochastic service times, patient unpunctuality, delays and interruptions of the provider and presences of no-shows. This study analyzed several scenarios with overbooking, and tested the main policies with a simulation model, proposing the most appropriate for the clinic. The 18 scheduling policies applied were found through an extensive systematic review of the literature. With the use of the OFFSET scheduling policy, it was possible to increase the number of appointments by 30 percent to the scheduling of the main clinic provider, maintaining the level of service provided. In addition, a new scheduling policy, called DOME CYCLE, was proposed, which has outperformed the other policies in the average of the tests performed.
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Coskun, Risvan. "SIMEX: A simulation-based expert production scheduling system." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/10286.
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A good methodology for production scheduling can result in high efficiency in reducing manufacturing costs. SIMEX is an experimental simulation-based expert production scheduler developed by the author for applications in flexible flow shop systems in a dynamic factory environment. This study introduces the general framework of SIMEX. A prototype is developed on an IBM compatible PC in Prolog, MODSIM II, Visual Basic, and Visual C++ to generate feasible and acceptable schedules with a synchronous data exchange facility. In general, primary tasks of SIMEX are to meet due dates of the final products, to increase throughput by reducing the number of setups, and to reduce inventory cost in a flexible flow shop system in real time. SIMEX has also an ability to change its expert system's rule base interactively by means of a user interface. The expert system module of SIMEX allows to use heuristics, and production rules which are the simplifications that help limit the search for possible problem solutions and handling unexpected events. Simulation-based scheduler written in MODSIM II, is another module of SIMEX. It generates the schedules, repeatedly, to analyze and verify proposed design and alternatives. (Abstract shortened by UMI.)
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Andersson, Martin. "Industrial scheduling with evolutionary algorithms using a hybrid representation." Thesis, Högskolan i Skövde, Institutionen för teknik och samhälle, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-5348.
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Scheduling problems have been studied extensively in the literature but because they are so hard to solve, especially real-world problems, it is still interesting to find ways of solving them more efficiently. This thesis aims to efficiently solve a real-world scheduling problem by using a hybrid representation together with an optimisation algorithm. The aim of the hybrid representation is to allow the optimisation to focus on the parts of the scheduling problem where it can make the most improvement. The new approach used in this thesis to accomplish this goal, is the combination of simulation-based optimisation using genetic algorithms and dispatching rules. By using this approach, it is possible to investigate the effect of putting specified job sequences in certain machines and using dispatching rules in the other. The hypothesis is that the optimisation can use dispatching rules on non-bottleneck machines that have little impact on the overall performance of the line and some specified job sequences on bottleneck machines that are hard to be scheduled efficiently with dispatching rules. This would allow the optimisation to focus on the bottleneck machines and that would produce a more efficient search. The results from the case study shows it is a viable approach exceeding or equalling existing techniques. The hypothesis that the optimisation can focus its efforts is supported by a bottleneck analysis which corresponds with the experimental results from optimisations.
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Saxena, Ashish. "Process simulation and scheduling in a multipurpose dairy plant." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0020/MQ27541.pdf.
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Pimentel, Ernani Falcao. "A two-pass scheduling method using discrete event simulation." Thesis, University of Warwick, 1996. http://wrap.warwick.ac.uk/66922/.
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The scheduling area is well known to generate large combinatorial problems and several modelling techniques have been used to tackle them. One of the most important techniques is Discrete Event Simulation (DES). However, as any other technique DES has its advantages and disadvantages. The main advantage of DES as a scheduling tool is the computational efficiency with which an accurate model of a manufacturing system can be developed. The disadvantage of DES as a scheduling tool is that a schedule is developed through incremental decisions over time, but without appreciation of the effect of each decision on the rest of the schedule. This thesis presents a two-pass finite scheduling method to alleviate the inherent disadvantage of DES as a scheduling tool. The two-pass method is based on two programs which employ a two-phase simulation model. The first pass produces schedules by simple heuristic dispatching rules (first in first out, earliest due date and slack time divided by the number of operations remaining). The second pass of the method tries to improve the schedule based on information from the first pass and a heuristic algorithm designed to improve the production flow. Results from the experiments carried out to test the effectiveness of the method are also presented.
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Löhndorf, Nils, and Stefan Minner. "Simulation Optimization for the Stochastic Economic Lot Scheduling Problem." Taylor and Francis, 2013. http://dx.doi.org/10.1080/0740817X.2012.662310.
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We study simulation optimization methods for the stochastic economic lot scheduling problem. In contrast to
prior research, we focus on methods that treat this problem as a black box. Based on a large-scale numerical
study, we compare approximate dynamic programming with a global search for parameters of simple control
policies. We propose two value function approximation schemes based on linear combinations of piecewise-
constant functions as well as control policies that can be described by a small set of parameters. While
approximate value iteration worked well for small problems with three products, it was clearly outperformed
by the global policy search as soon as problem size increased. The most reliable choice in our study was a
globally optimized fixed-cycle policy. An additional analysis of the response surface of model parameters on
optimal average cost revealed that the cost effect of product diversity was negligible. (authors' abstract)
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Vargas-Morales, Juan. "DATA TRANSMISSION SCHEDULING FOR DISTRIBUTED SIMULATION USING PACKET A." Doctoral diss., University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2785.
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Communication bandwidth and latency reduction techniques are developed for Distributed Interactive Simulation (DIS) protocols. Using logs from vignettes simulated by the OneSAF Testbed Baseline (OTB), a discrete event simulator based on the OMNeT++ modeling environment is developed to analyze the Protocol Data Unit (PDU) traffic over a wireless flying Local Area Network (LAN). Alternative PDU bundling and compression techniques are studied under various metrics including slack time, travel time, queue length, and collision rate. Based on these results, Packet Alloying, a technique for the optimized bundling of packets, is proposed and evaluated. Packet Alloying becomes more active when it is needed most: during negative spikes of transmission slack time. It produces aggregations that preserve the internal PDU format, allowing the resulting packets to be subjectable to further bundling and/or compression by conventional techniques. To optimize the selection of bundle delimitation, three online predictive strategies were developed: Neural-Network based, Always-Wait, and Always-Send. These were compared with three offline strategies defined as Type, Type-Length and Type-Length-Size. Applying Always-Wait to the studied vignette using the wireless links set to 64 Kbps, a reduction in the magnitude of negative slack time from -75 to -9 seconds for the worst spike was achieved, which represents a reduction of 88 %. Similarly, at 64 Kbps, Always-Wait reduced the average satellite queue length from 2,963 to 327 messages for a 89% reduction. From the analysis of negative slack-time spikes it was determined which PDU types are of highest priority. The router and satellite queues in the case study were modified accordingly using a priority-based transmission scheduler. The analysis of total travel times based of PDU types numerically shows the benefit obtained. The contributions of this dissertation include the formalization of a selective PDU bundling scheme, the proposal and study of different predictive algorithms for the next PDU, and priority-based optimization using Head-of-Line (HoL) service. These results demonstrate the validity of packet optimizations for distributed simulation environments and other possible applications such as TCP/IP transmissions.Ph.D.
Department of Electrical and Computer Engineering
Engineering and Computer Science
Computer Engineering
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Grossman, Michael D. "A computer simulation of processor scheduling in UNIX 4.2BSD /." Online version of thesis, 1987. http://hdl.handle.net/1850/10295.
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Range, Ashleigh Royalty. "Improving surgical patient flow through simulation of scheduling heuristics." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81017.
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Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division; in conjunction with the Leaders for Global Operations Program at MIT, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 79).
Massachusetts General Hospital (MGH) is currently the nation's top ranked hospital and is the largest in New England. With over 900 hospital beds and approximately 38,000 operations performed each year, MGH's operating rooms (ORs) run at 90% utilization and their hospital beds at 99% operational occupancy. MGH is faced with capacity constraints throughout the perioperative (pre-, intra-, and postoperative) process and desires to improve throughput and decrease patient waiting time without adding expensive additional resources. This project focuses on matching the intraday scheduling of elective surgeries with the discharge rate and pattern of patients from the hospital floor by investigating ways surgeons could potentially schedule their cases within a given OR block. To do this, various scheduling rules are modeled to measure the impact of shifting patient flow in each step of the perioperative process. Currently the hospital floor proves to be the biggest bottleneck in the system. Delays in discharging patients result in Same Day Admits (patients that will be admitted to the hospital post-surgery) waiting for hospital beds in the Post Anesthesia Care Unit (PACU). These patients wait more than sixty minutes on average after being medically cleared to depart the PACU. A simulation model is built to evaluate the downstream effects of each scheduling rule and discharge process change. The model takes into account physical and staff resource limitations at each of the upstream and downstream steps in the perioperative process. By scheduling Same Day Admits last in each OR block, patient wait time in the PACU can be reduced up to 49%. By implementing the recommended changes the system will realize lower wait times for patients, less stress on the admitting and nursing staff, and a better overall use of the limited physical resources at MGH.
by Ashleigh Royalty Range.
S.M.
M.B.A.
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Chen, Bilin, and Ida Karlsson. "Simulation of an Electric Quarry with Automated Transporter Scheduling." Thesis, KTH, Optimeringslära och systemteori, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235532.
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An electric site project is being developed by Volvo Construction Equipment with the goal to transform the quarry and aggregate industry by reducing carbon emissions by up to 95 % and total ownership cost up to 25 %. The goal is achieved by using electrical autonomous vehicles as the work force. In an effort to reduce lead times, from design to reality, the objective of this thesis was to develop a logical architecture of a quarry using the Systems Modelling Language. The logical model contains all the essential elements existent in a quarry and describes core behavior to reflect the requirements needed in an electric site. The value of the logical model lies in its ability to aid the development process, complementing it with an executable simulation further show-cases that value. The simulation was used to analyze the performance of the electrical autonomous transporter HX02 that is instructed by an algorithm for optimal routing and scheduling. The algorithm incorporates traffic to reduce congestion at vertices with high level of activity. Its robustness is evaluated by varying the number of transporters and the weight on the traffic cost in the cost function. It was found that applying the traffic cost helped reduce the congestion significantly and increased production, but at the cost of more battery usage. The effect of incorporating traffic was most noticeable when there were more than 10 transporters operational. But when the weight on the traffic cost was too large, the production declined instead. The observed time complexity of the algorithm was O(n2), which was feasible due to a small input size n.Ett elektriskt stenbrottsprojekt drivs av Volvo Construction Equip-ment med målet att omvandla hela gruvindustrin. Målet är att minska koldioxidutsläppen med upp till 95% och det totala ägarskapskostnaden upp till 25%. För att uppnå målet ska elektriska autonoma maskiner användas i stenbrotten. I syfte att minska ledtiden från design till verklighet, var målet med denna avhandling att utveckla en logisk arkitektur av stenbrottet med Systems Modelling Language. Den logiska modellen innehöll väsentliga element som återfinns i ett stenbrott och beskriver kärnbeteenden för att återspegla de krav som uppstår i ett elektriskt stenbrott. För att ytterligare påvisa värdet som den logiska modellen besitter och framföra dess betydelse i rollen att stödja utvecklingsprocessen, skapades en exekverbar simulering som ett komplement. Simuleringen användes för att analysera prestandan hos den elektriska autonoma dumpern HX02 som fick instruktioner av en algoritm för optimal ruttplanering. Algoritmen tog hänsyn till trafiken på området för att minska trafik-stockning vid noder med hög aktivitetsnivå. Dess robusthet utvärderades genom att variera på antalet dumprar och vikten på trafikkostnaden i kostnadsfunktionen. Det visade sig att introducera trafik bidrog till avsevärt minskad trafikträngsel och ökade produktionen, men på bekostnaden av en högre batteriåtgång. Trafikkostnadens påverkan var som tydligast när antalet verk-samma dumprar var högre än 10. Men när trafikkostnaden viktades för högt, minskade produktionen istället. Tidskomplexiteten hos algoritmen är O(n2) vilket är acceptabelt då mängden indata n är liten.
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Kunaka, Charles. "Modelling paratransit services : a microscopic simulation approach." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243829.
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Paratransit operations in cities in developing countries play an important role in public transport provision. The operations are run within the realm of the infonnal sector and are highly flexible. There are numerous operators running one or two vehicles on a cash basis. This and other issues contribute to the problems with the services that are provided. Poor reliability and stability in supply are the main problems. Despite these serious problems, there has been little research on possible solutions to resolve them. The present study is aimed at improving understanding of the operation of such systems. It assesses the effects on users and operators of different routing, stopping and scheduling regimes. A new model of paratransit operations is developed. The problem of paratransit operations is conceptualised in terms of interactions between demand and supply. The interactions take place in time and geographical space and are shaped by the actions taken by individual users and individual vehicle operators. The model is designed to overcome some of the restrictions on the definitions of time - and in particular space - that are found in existing methodologies. A modelling approach designed to represent the two dimensions as realistically as possible was adopted. Two techniques are central to the construction of the model. Simulation techniques are used to model the temporal processes and a Geographical Information System (GIS) for the spatial processes. The two are complementary to overcome the inherent weaknesses in either approach. Modules are developed to represent demand and supply at a microscopic level. The Model of Paratransit Services (MOPS) involves interfacing a GIS and external modules for dynamic processes. The model was validated against field data collected in Harare, Zimbabwe. Experiments were run for a case study area and the results that were obtained on routing, stopping and scheduling regimes are reported in developing countries.
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Lu, Bingfeng. "Simulation and evaluation of a new scheduling algorithm, integrating pre-run-time scheduling with run-time scheduling of real-time processes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ33496.pdf.
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Monze, Mweene James. "Cost and performance analysis of manufacturing systems with object-oriented simulation." Thesis, University of Sussex, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239461.
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PRATHY, PRAVEEN KUMAR. "SIMULATION AND HEURISTIC SCHEDULING OF GROUND TRAFFIC AT AN AIRPORT." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1092853121.
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Babur, Ozgur. "A Simulation Study Of Scheduling Algorithms For Packet Switching Networks." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/2/1219336/index.pdf.
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A scheduling algorithm has the primary role in implementing the quality of service guaranteed to each flow by managing buffer space and selecting which packet to send next with a fair share of network. In this thesis, some scheduling algorithms for packet switching networks are studied. For evaluating their delay, jitter and throughput performances, a discrete event simulator has been developed. It has been
seen that fair scheduling provides, fair allocation of bandwidth, lower delay for sources using less than their full share of bandwidth and protection from ill-behaved
resources.
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Lemanski, Michael J. Benton Jesse C. "Simulation for Smartnet scheduling of asynchronous transfer mode virtual channels /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA333481.
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Roberg, Kristoffer. "Simulation of scheduling algorithms for femtocells in an LTE environment." Thesis, Linköping University, Communication Systems, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-59651.
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The new mobile standard Long Term Evolution delivers high data rates, small delay and a more efficiently utilized RF spectrum. A solution to maintain this performance in user dense areas or areas with bad reception is the deployment of so-called femtocells. Femtocells are small base stations that are deployed indoors and share the RF spectrum with the whole mobile network. The idea is that femtocells will increase mobile operators network coverage and capacity while it at the same time increase users data throughput. There are several challenges with femtocells, both technical and economical ones. The most debated issues is how femtocells should schedule users while operating in an environment where other femtocells and base stations are interfering. In this work we developed a simulation tool to simulate the scheduling interaction between femtocells and base stationsin order to show the performance of radio resource schedulers. This rapport also aims to evaluate an approach to a femtocell scheduler to solve this issue in a satisfying way. The report gives a description of the structure of the implemented simulation tool together with some reflections on how future designs of similar or more complex simulation environments could be done.
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Lemanski, Michael J., and Jesse C. Benton. "Simulation for Smartnet scheduling of asynchronous transfer mode virtual channels." Monterey, California. Naval Postgraduate School, 1997. http://hdl.handle.net/10945/8961.
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Approved for public release; Distribution is unlimitedCritical to the success of all future battlefield commanders is the rapid retrieval of relevant, time sensitive information. Some of this information will be available locally while the remainder is stored in the United States. DARPA's Battlefield Awareness and Data Dissemination (BADD) program attempts to deliver heterogeneous data to the battlefield using Asynchronous Transfer Mode (ATM) protocol. ATM was originally designed to implement dynamic virtual channels over duplex, high-speed, high capacity fiber optic cabling. The problem addressed was to determine which algorithm best schedules calls on BADD's ATM network that uses static virtual channels over simplex, error prone, long delay, satellite links. Because the BADD project uses ATM in such an unusual way, and because of the need to determine a schedule for transmissions over the heterogeneous static channels, we modeled BADD using the state-of-the-art network simulation tool, Optimized Network Engineering Tools (OPNET). We determined several modifications that must be made to existing network simulators to allow them to model next-generation networks. Our simulation shows that a greedy algorithm yields a 53% decrease in the overall completion time and a 46% increase in average bit throughput over FIFO scheduling
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Peng, Yidong. "Applying Simulation and Genetic Algorithm for Patient Appointment Scheduling Optimization." Thesis, North Dakota State University, 2013. https://hdl.handle.net/10365/27015.
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In this study, we discuss the implementation of integrated simulation and genetic algorithm for patient scheduling optimization under two different settings, namely the "traditional" scheduling system and the "open access" scheduling system. Under the "traditional" setting, we propose a two-phase approach for designing a weekly scheduling template for outpatient clinics providing multiple types of services. Our results demonstrate that the two-phase approach can efficiently find the promising weekly appointment scheduling templates for outpatient clinics. Under the "open access" setting, we propose a discrete event simulation and genetic algorithm (DES-GA) approach to find the heuristic optimal scheduling template for the clinic allowing both open access and walk-in patients. The solution provides scheduling templates consisting of not only the optimal number of reservations for open access appointments and walk-ins, but also the optimized allocation of these reserved slots, by minimizing the average cost per admission of open access or walk-in patient.
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Wang, Qihe. "Scheduling and Simulation of Large Scale Wireless Personal Area Networks." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1148050113.
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Islam, Md Rubayat Ul. "Utilizing Scenario Based Simulation Modeling to Optimize Aircraft Fleet Scheduling." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1560965666900518.
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Rahin, Mohammad A. "Parallel scheduling of concurrent VLSI simulation modules onto a multiprocessor." Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/27133.
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The first of the two algorithms examined is the Concurrent Recursive Binary Partitioning (CRBP). This heuristic is based on Kernighan-Lin's graph bi-partitioning algorithm. An L-way partition is achieved by applying binary partitioning recursively, the procedure taking the form of a binary tree. In its parallel implementation each node of this tree is executed independently by a group of available processors and only the best among the solutions obtained is accepted. This provides enhanced processor utilisation and also assures improved results. The factors affecting the performance of the L-way partitioning heuristic at different stages are examined and their optimum values are investigated.
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Parsons, Russell M. "The requirements for a generic interface to support the integration of simulation and production scheduling." Thesis, University of Sunderland, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269003.
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Hammar, Mattias. "Parallelization of Aggregated FMUs using Static Scheduling." Thesis, Linköpings universitet, Programvara och system, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-152272.
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This thesis implements and evaluates static scheduling for aggregated FMUs. An aggregate FMU is several coupled FMUs placed in a single FMU. The implementation creates task graphs from the internal dependencies and connections between the coupled FMUs. These task graphs are then scheduled using two different list scheduling heuristics, MCP and HLFET. The resulting schedules are then executed in parallel by using OpenMP in the runtime. The implementation is evaluated by looking at the utilization of the schedule, the execution time of the scheduling and the speedup of the simulation. These measurements are taken on three different test models. With model exchange FMUs only a really small speedup is observed. With co-simulation models the speedup varies a lot depending on the model, the highest achieved speedup was 2.8 running on four cores.
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Benndorf, Jorg. "Efficient sequential simulation methods with implications to long-term production scheduling /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18756.pdf.
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Krige, David. "Simulation-based online scheduling of a make-to-order job shop." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2283.
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Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2009.Scheduling is a core activity in the manufacturing business. It assists with efficient and effective utilization of capital-intensive resources and increased throughput, thus increasing profitability. The focus in this thesis is on scheduling of manufacturing orders in a make-to-order job-shop enterprise. It is widely accepted that manufacturing of large volumes and production with as few as possible product variants is the most cost-effective business approach, but the need for low volume, once-off engineering parts will always exist. Many approaches to scheduling exist, including translation of a scheduling problem to a Travelling Salesman analogue, while Discrete-event computer simulation is well established as a means to assist with scheduling. Simulation is appealing in the manufacturing environment, as it can realistically imitate dynamic, stochastic processes while being descriptive in forecasting the future. In this thesis, the development and testing of a simulation-based scheduler is described. The scheduler was developed for, and in collaboration with a South African make-to-order job-shop enterprise. A supporting information system was also developed and it is required that the enterprise changes some of its business processes if this scheduler is implemented. The scheduler considers the status of the enterprise each time a new order is received, and the current schedule is reviewed and may be revised at such a point in time, making it a real-time scheduler. Several classic scheduling dispatching rules and –measures were incorporated in the scheduler. These include First-in First-out, Earliest Due Date, Longest Processing Time, Shortest Processing Time, Smallest Slack and Critical Ratio (dispatching rules), while the performance measures are Makespan, Earliness, Lateness, Average Flow Time and Machine Usage. The proposed scheduler has been verified and validated using test data and designed confidence building tests, and its performance was also compared to an actual, historical schedule. The functioning of the scheduler is finally demonstrated using a stochastic test environment. The scheduler has generally performed satisfactorily and should be implemented as the final phase of this project.
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Håkansson, Rebecka. "Staff scheduling in elderly care - A simulation study of trade-offs." Thesis, Linköpings universitet, Optimeringslära, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-115754.
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Numerous studies have been done in the area of nurse scheduling, since this is a complex area with a lot of aspects that has to be taken into account. An interesting but little studied subject is how the requirements for the scheduling affect the possibility to construct a feasible schedule, or how the requirements affect the quality of the schedule. Of special interest is the effect of the composition of the workforce and of the change in scheduling rules. What is missing is results showing which composition and changes that are possible, and if so what is needed to be able to follow through with them. The changes tested in our simulation study are changes that is up for discussion at many wards in Sweden today, with topics such as split shifts and high part-time work percentages within the staff. In order to simulate various scheduling requirements and changes, an integer linear model for creating nurse schedules is developed. The results provide some insight into the dependence between scheduling requirements and the resulting schedules. In particular our simulation results indicate that there is an inherent conflict between high part-time work percentages and split or long work shifts. Our results can be used as a basis for future research on these topics in the area of nurse scheduling.
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Ullo, Silvia Liberata. "Evaluation of scheduling strategies in a semiconductor wafer fab using simulation." Thesis, Massachusetts Institute of Technology, 1992. https://hdl.handle.net/1721.1/128456.
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Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1992.Includes bibliographical references (leaves 105-107).
by Silvia Liberata Ullo.
Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1992.
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Saremi, Alireza. "Mathematical programming enhanced metaheuristic approach for simulation-based optimization in outpatient appointment scheduling." Elsevier, 2013. http://hdl.handle.net/1993/21710.
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In the last two decades, the western world witnessed a continuous rise in the health expenditure. Meanwhile, complaints from patients on excessive waiting times are also increasing. In the past, many researchers have tried to devise appointment scheduling rules to provide trade-offs between maximizing patients’ satisfaction and minimizing the costs of the health providers. For instance, this challenge appears appointment scheduling problems (ASP).
Commonly used methods in ASP include analytical methods, simulation studies, and combination of simulation with heuristic approaches. Analytical methods (e.g., queuing theory and mathematical programming) face challenges of fully capturing the complexities of systems and usually make strong assumptions for tractability of problems. These methods simplify the whole system to a single-stage unit and ignore the actual system factors such as the presence of multiple stages and/or resource constraints. Simulation studies, conversely, are able to model most complexities of the actual system, but they typically lack an optimization strategy to deliver optimal appointment schedules. Also, heuristic approaches normally are based on intuitive rules and do not perform well as standalone methods.
In order to reach an optimal schedule while considering complexities in actual health care systems, this thesis proposes efficient and effective methods that yield (near) optimal appointment schedules by integrating mathematical programming, a tabu search optimization algorithm and discrete event simulation. The proposed methodologies address the challenges and complexities of scheduling in real world multistage healthcare units in the presence of stochastic service durations, a mix of patient types, patients with heterogeneous service sequence, and resource constraints.
Moreover, the proposed methodology is capable of finding the optimum considering simultaneously multiple performance criteria. A Pareto front (a set of optimal solutions) for the performance criteria can be obtained using the proposed methods. Healthcare management can use the Pareto front to choose the appropriate policy based on different conditions and priorities.
In addition, the proposed method has been applied to two case studies of Operating Rooms departments in two major Canadian hospitals. The comparison of actual schedules and the ones yielded by the proposed method indicates that proposed method can improve the appointment scheduling in realistic clinical settings.
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Mahjub, Hossein. "Logistic discrimination, screening and the simulation of a heart surgery department." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308030.
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Elyamak, Alaa Mustapha. "Fleet Sizing and Scheduling Model of Container Carriers between Two Ports." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_theses/170.
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Globalization and containerization have changed the shipping industry and carriers are challenged to reshape their operational planning in order to maintain their market share. The objective of this paper is to formulate a model to determine the optimal fleet size and sailing frequency that minimizes total shipping and inventory (wait) costs for a container shipping company. The proposed model assumes an arrival process that follows a Poisson rate. We first consider unlimited ship capacity and propose a solution to determine the required fleet size and the optimal sailing frequency. We then extend the work to consider limited ship capacity. Furthermore, we introduce a cost component associated with outsourcing shipments due to insufficient capacity. The outsourced shipment is utilized when the number of containers at a port exceeds the available capacity. In the general case, a closed form solution could not be derived. Therefore, a simulation study is undertaken to analyze optimal fleet sizing, scheduling, and outsourcing policies under varying paramaters. Our study investigates the trade-off between building capacity and outsourcing in the context of cargo shipment. The model proves to be a reliable tool to determine optimal delay time at ports and optimal fleet size.
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Qiu, Xueni, and 邱雪妮. "Artificial immune systems for job shop scheduling problems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49617576.
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Effective process scheduling is very important to the modern manufacturing production. This research addresses a classical scheduling problem — the job shop scheduling problem from the standpoint of both static and dynamic environment. In this study, the job shop scheduling problem (JSSP) is investigated in three aspects: (1) static JSSP that operates under a static scheduling environment with known information about the jobs and machines without unexpected events; (2) semi-dynamic JSSP which is developed based on static JSSP but violating the non-operation disruption assumption due to the presence of uncertainties occurring in the dynamic scheduling process; (3) dynamic online JSSP that operates under a dynamic operating environment in which jobs continuously arrive that are accompanied by unpredictable disruptions, such as machine failures. In the thesis, these three types of JSSP are solved by artificial immune systems (AIS) based algorithms.
For static JSSP, a hybrid algorithm is proposed based on clonal selection theory and immune network theory of AIS, and particle swarm optimization (PSO). The clonal selection theory establishes the framework of the hybrid algorithm, while the immune network theory is applied to increase the diversity of antibody set which represents the solution candidates. The proposed framework involves the processes of selection, cloning, hypermutation, memory, and receptor editing. The PSO is designed to optimize the hypermutation process of the antibodies to accelerate the search procedure. This hybrid algorithm is tested with benchmark problems of different sizes and is compared with other methods. The results demonstrate the efficiency of the proposed algorithm, the effectiveness of PSO, and the contribution of long-lasting memory which is one of the key features of AIS.
The semi-dynamic JSSP is handled by the rescheduling process. An extended deterministic dendritic cell algorithm (dDCA) is proposed to control the rescheduling process under considerations of the stability and efficiency of the scheduling system. The main role of the extended dDCA is to quantify the negative effect generated from the unexpected disturbances and to determine the best time to trigger the rescheduling process. This algorithm is tested on static benchmark problems with the existence of different kinds of disruptions. The experimental results demonstrate its capability of timely triggering the rescheduling process.
The dynamic online JSSP is modeled as a multi-objective optimization problem. In this case, the immune network theory of AIS is hybridized with priority dispatching rules (PDRs) to establish the idiotypic network model for dispatching rules. This idiotypic network model drives the dispatching rule selection process under a dynamic scheduling environment. Based on the job shop situations represented by the antigens, the dispatching rules that perform best under specific conditions are selected as the antibodies of the idiotypic network model.
Finally, the thesis proposes a generic framework of JSSP that combines the three different aspects studied in this research with corresponding scheduling strategies. The scheduling framework for a job shop system consists of four collaborating modules and is designed to solve various scheduling situations efficiently under a dynamic operating environment.published_or_final_version
Industrial and Manufacturing Systems Engineering
Doctoral
Doctor of Philosophy
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Manuputty, James David. "Shipbuilding evaluation using neural network based response surface and adaptive optimisation." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366515.
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Ballard, Sarah M. "Simulation analysis of capacity and scheduling methods in the hospital surgical suite /." Online version of thesis, 2007. http://hdl.handle.net/1850/3927.
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Patvivatsiri, Lisa. "A Simulation-Based Approach for Optimal Nurse Scheduling in an Emergency Department." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/43867.
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The purpose of this research is to determine an appropriate nurse staffing strategy for the Intermediate Care Unit (ICU) and the Critical Care Unit (CCU) of the Emergency Department at York Hospital in York, Pennsylvania. This strategy must adhere to certain administrative policies while keeping patient waiting times within allowable limits. Determining the proper number of resources in an emergency department is a difficult problem because while assistance must be provided without delay at any time, the available resources are restricted by the hospital budget. This research involves simulating the operations of the Emergency Department at York Hospital using the software package Arena 7.0 to evaluate how the system is impacted by various nurse staffing strategies. A microcomputer-based decision support system (DSS) for nurse scheduling that was first developed by Sitompul in 1991 has been implemented using Turbo Pascal 6.0 to generate twenty possible nurse staffing plans. The best alternative staffing plan has been evaluated by the simulation model to determine its effect on waiting times for patients. Specifically, patients are divided into five ESI levels, where ESI-1 patients are the most serious and ESI-5 patients are the least serious, and waiting times are provided for each patient type.
While the DSS approach is useful in generating specific working schedules that are acceptable to the nurses' requirements, it is limited when developing an overall staffing plan. Specifically, the DSS requires a user-defined ratio of nurses working the various shifts, and this ratio must remain constant throughout each month even if patient arrival rates are known to be time dependent. As an alternative approach, OptQuest for Arena was employed to search for an overall nurse staffing plan. After providing Arena with 50 DSS-generated schedules that satisfy the nurses' requirements, OptQuest was used to determine the best schedule for each nurse to follow in order to minimize the average waiting time in the system for patients. Although the average waiting time obtained by the OptQuest staffing plan decreased from the current staffing plan for all patient types, a paired-t comparison determined using Arena's Output Analyzer indicated no statistical difference (at the 95% confidence level) between the DSS and OptQuest scenarios, in terms of the average waiting time for ESI-1 and ESI-2 patients. Further analysis indicated that a system bottleneck occurred in the triage area of the emergency department during evening hours. After adding one additional triage nurse in the evening shift, the OptQuest-generated staffing plan was re-evaluated. The results indicate that the suggested staffing plan reduced the average waiting time in the current staffing plan by 34.33%, 32.73%, 47.87%, 54.92%, and 52.41% for ESI-1, ESI-2, ESI-3, ESI-4, and ESI-5 patients, respectively. In addition, the average waiting time of ESI-1, ESI-2, ESI-3, ESI-4, and ESI-5 patients for the suggested staffing plan was 19.27%, 19.36%, 39.37%, 48.55%, and 46.64%, respectively, less than for the staffing plan determined when using the DSS approach alone.Master of Science
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Bhargava, Priyanka. "Real-time production scheduling in ERP systems using a simulation based approach." Diss., Online access via UMI:, 2006.
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Hui, Tsai-Chiu, and 蔡秋慧. "Integrate Scheduling Networks with Simulation for Scheduling with Resource Constraints." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/6qxx9k.
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碩士朝陽科技大學
營建工程系碩士班
94
Critical Path Method (CPM) is one of the most frequently used scheduling techniques. Therefore, most of the construction project planners/engineers or managers adopt CPM to draw schedule network. In addition, many kinds of commercial scheduling software also integrate CPM into their system. Despite its popularity, there are several drawbacks for employing CPM technique or network in the analysis of construction processes. One of the defects is that people could not use CPM to examine the effect such as lowering project cost or compressing project duration by testing different resource combinations. Although through the progress of information technology, commercial scheduling software such Microsoft Project and Primavera P3 provides the function that allow user to input resource requirement in CPM network and then calculate the project duration. However, the commercial software still lack of the capability to find the best resource utilization of the construction operation if there are many resource combinations can be tested. On the other hand, computer simulation techniques are good at performing such analysis. As a result, many researches are dedicated in the enhancement of the capability for computer simulation technique providing the function of optimizing resource utilizations for the construction system. However, computer simulation systems such as MicroCYCLONE, COOPS or STROBOSCOPE often require user to learn their modeling elements and thus establish modeling network to be run in the simulation systems. To successfully running simulation, the modeling network has to be built as precise as possible. An obstacle for project planner to use simulation technique to optimize the resource assignments is that they are lacking of simulation modeling skills. Since most planners are familiar with the use of CPM technique, this research is aiming at developing computer program that allows users input information as they apply in CPM and then transfers CPM network to simulation model. This research uses COST (Construction Operations Simulation Tool) simulation system whose development is supported by national science council as the platform and establish an interface that allow users to input information as they usually do for commercial scheduling software. The new system should transfer input information into simulation model automatically and then run simulation. The results obtained from running simulation will then be used for deciding the projection duration as well as what resource combination should be selected to reflect the duration decided.
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Lu, Guan-Yin, and 陸冠吟. "A Lean Production Simulation Scheduling System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/82609626712039735697.
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碩士國立雲林科技大學
工業工程與管理研究所碩士班
101
Because of difficult prerequisite (leveling production) and late in computerization, the application range of Lean Production is restricted. Therefore, we conceive to make conventional ERP work with lean production, that is to say the push system would be compatible with lean. To accomplish this goal, we have to design Lean Production Tracking and Control System (Lean SFT) and Lean Production Simulation Scheduling System (Lean Intelligent Factory Scheduling system, Lean iFS). This paper focus on planned Lean iFS, but carry on with Lean SFT in the same time and referred to each other. To verify delivery schedule by simulation scheduling, production manager can adjust shop loading or delivery date according to schedule result, and take more benefits to enterprise by relax the restrictions of leveling production. Furthermore, this study discusses the results of experiment in Solar Cell case, the results show there is possible to turn push manufacturing into lean production, and make enterprise more competitive and flexible in this produce way.
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Yeh, Hsin-chi, and 葉信岐. "A Self WIP-Adjusting Simulation Scheduling - A Solar Cell Production Scheduling Example." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/79402232042369271561.
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碩士國立雲林科技大學
工業工程與管理研究所碩士班
100
In the traditional Push Manufacturing, the idea of scheduling mostly pursues mass production. As a result, some products are surplus and there are excessive accumulations of products waiting for processing in the bottleneck. By literatures, knowing that the cycle time will increase when the system accumulate too much work in process; likewise the influences of the bottleneck control for WIP are great. The Theory of Constraints provides some new ideas of these problems and get good effects. However, when we examined the common variety of releasing, dispatching rules, we found that there are still some unsolved problems. Therefore, this study develops a WIP controlled mechanism that realizes to the concept of TOC, called “A Self WIP-Adjusting Simulation Scheduling”. It also designs and implements this mechanism with the control methods of all kinds of rules based on WIP control group. Finally, integrated with Enterprise Resource Planning system and implemented as an Intelligent Factory Scheduling system (iFS) prototype. In this study, the solar cell example obtains scheduling results in the current batch mode. Compared with the current plans and literatures plans, it obtains good results. In the meantime, we also discuss better batch ways and then come to better results. Finally, the comparison between traditional DBR and iFS shows our research has nice controls of the scheduling after the bottleneck wandered.
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Kao, Chia-chun, and 高嘉俊. "A Simulation Study on Operation Room Scheduling." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/v3kmyt.
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碩士國立中山大學
應用數學系研究所
103
Controling the running cost of the operating rooms is one of the key points for the hospital management. The cost of operating rooms is high consumption items for the hospital. The effectiveness of operating room is associated with the operating scheduling. Because there are some restrictions for the operating scheduling, for example, the working schedules of doctors or restrictions on the use of the operating rooms. So operating scheduling usually depends on experienced staffs. However, if the schedule is not good enough, it may cause the overtime probability become too high or the utilization rate too low. This work uses data set from the gynecology department of a major teaching hospital in southern Taiwan. Mixture log-normal distributions are identified to be acceptable statistically in describing the operating times. We estimate the overtime probabilities and corresponding costs according to the combinations of different operating types. In the process of making up the schedules, measures are assigned according to the operating types as well as their status. Moreover, there may also be some restrictions with respect to misjudgment of the operating status by the doctors due to possible unexpected complications during the operations. Here, we provide a scheduling strategy, called the minimum scoring strategy, for minimizing the operating times based on the possible operations coming into the system and complying restrictions mentioned above, using the scoring measures assigned. From the simulation results, the proposed method can effectively reduce overtime probabilities and costs, as well as the idling times of the operating rooms.