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Hatami, Sara. "The Distributed and Assembly Scheduling Problem." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/64072.
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[EN] Nowadays, manufacturing systems meet different new global challenges and
the existence of a collaborative manufacturing environment is essential to face
with. Distributed manufacturing and assembly systems are two manufacturing
systems which allow industries to deal with some of these challenges. This
thesis studies a production problem in which both distributed manufacturing
and assembly systems are considered. Although distributed manufacturing
systems and assembly systems are well-known problems and have been extensively
studied in the literature, to the best of our knowledge, considering
these two systems together as in this thesis is the first effort in the literature.
Due to the importance of scheduling optimization on production performance,
some different ways to optimize the scheduling of the considered problem are
discussed in this thesis.
The studied scheduling setting consists of two stages: A production and an
assembly stage. Various production centers make the first stage. Each of these
centers consists of several machines which are dedicated to manufacture jobs.
A single assembly machine is considered for the second stage. The produced
jobs are assembled on the assembly machine to form final products through a
defined assembly program.
In this thesis, two different problems regarding two different production
configurations for the production centers of the first stage are considered.
The first configuration is a flowshop that results in what we refer to as the
Distributed Assembly Permutation Flowshop Scheduling Problem (DAPFSP).
The second problem is referred to as the Distributed Parallel Machine and
Assembly Scheduling Problem (DPMASP), where unrelated parallel machines
configure the production centers. Makespan minimization of the product on the
assembly machine located in the assembly stage is considered as the objective
function for all considered problems.
In this thesis some extensions are considered for the studied problems
so as to bring them as close as possible to the reality of production shops.
In the DAPFSP, sequence dependent setup times are added for machines in
both production and assembly stages. Similarly, in the DPMASP, due to
technological constraints, some defined jobs can be processed only in certain
factories.
Mathematical models are presented as an exact solution for some of the
presented problems and two state-of-art solvers, CPLEX and GUROBI are
used to solve them. Since these solvers are not able to solve large sized
problems, we design and develop heuristic methods to solve the problems. In
addition to heuristics, some metaheuristics are also designed and proposed to
improve the solutions obtained by heuristics. Finally, for each proposed problem,
the performance of the proposed solution methods is compared through
extensive computational and comprehensive ANOVA statistical analysis.<br>[ES] Los sistemas de producción se enfrentan a retos globales en los que el concepto
de fabricación colaborativa es crucial para poder tener éxito en el entorno
cambiante y complejo en el que nos encontramos. Una característica de los sistemas
productivos que puede ayudar a lograr este objetivo consiste en disponer
de una red de fabricación distribuida en la que los productos se fabriquen en
localizaciones diferentes y se vayan ensamblando para obtener el producto
final. En estos casos, disponer de modelos y herramientas para mejorar el
rendimiento de sistemas de producción distribuidos con ensamblajes es una
manera de asegurar la eficiencia de los mismos.
En esta tesis doctoral se estudian los sistemas de fabricación distribuidos
con operaciones de ensamblaje. Los sistemas distribuidos y los sistemas con
operaciones de ensamblaje han sido estudiados por separado en la literatura.
De hecho, no se han encontrado estudios de sistemas con ambas características
consideradas de forma conjunta.
Dada la complejidad de considerar conjuntamente ambos tipos de sistemas
a la hora de realizar la programación de la producción en los mismos, se ha
abordado su estudio considerando un modelo bietápico en la que en la primera
etapa se consideran las operaciones de producción y en la segunda se plantean
las operaciones de ensamblaje.
Dependiendo de la configuración de la primera etapa se han estudiado dos
variantes. En la primera variante se asume que la etapa de producción está
compuesta por sendos sistemas tipo flowshop en los que se fabrican los componentes
que se ensamblan en la segunda etapa (Distributed Assembly Permutation
Flowshop Scheduling Problem o DAPFSP). En la segunda variante
se considera un sistema de máquinas en paralelo no relacionadas (Distributed
Parallel Machine and Assembly Scheduling Problem o DPMASP). En ambas
variantes se optimiza la fecha de finalización del último trabajo secuenciado
(Cmax) y se contempla la posibilidad que existan tiempos de cambio (setup)
dependientes de la secuencia de trabajos fabricada. También, en el caso
DPMASP se estudia la posibilidad de prohibir o no el uso de determinadas
máquinas de la etapa de producción.
Se han desarrollado modelos matemáticos para resolver algunas de las
variantes anteriores. Estos modelos se han resuelto mediante los programas
CPLEX y GUROBI en aquellos casos que ha sido posible. Para las instancias
en los que el modelo matemático no ofrecía una solución al problema se han
desarrollado heurísticas y metaheurísticas para ello.
Todos los procedimientos anteriores han sido estudiados para determinar
el rendimiento de los diferentes algoritmos planteados. Para ello se ha realizado
un exhaustivo estudio computacional en el que se han aplicado técnicas
ANOVA.
Los resultados obtenidos en la tesis permiten avanzar en la comprensión
del comportamiento de los sistemas productivos distribuidos con ensamblajes,
definiendo algoritmos que permiten obtener buenas soluciones a este tipo de
problemas tan complejos que aparecen tantas veces en la realidad industrial.<br>[CAT] Els sistemes de producció s'enfronten a reptes globals en què el concepte de
fabricació col.laborativa és crucial per a poder tindre èxit en l'entorn canviant
i complex en què ens trobem. Una característica dels sistemes productius
que pot ajudar a aconseguir este objectiu consistix a disposar d'una xarxa de
fabricació distribuïda en la que els productes es fabriquen en localitzacions
diferents i es vagen acoblant per a obtindre el producte final. En estos casos,
disposar de models i ferramentes per a millorar el rendiment de sistemes de
producció distribuïts amb acoblaments és una manera d'assegurar l'eficiència
dels mateixos.
En esta tesi doctoral s'estudien els sistemes de fabricació distribuïts amb
operacions d'acoblament. Els sistemes distribuïts i els sistemes amb operacions
d'acoblament han sigut estudiats per separat en la literatura però, en allò
que es coneix, no s'han trobat estudis de sistemes amb ambdós característiques
conjuntament. Donada la complexitat de considerar conjuntament ambdós
tipus de sistemes a l'hora de realitzar la programació de la producció en els
mateixos, s'ha abordat el seu estudi considerant un model bietàpic en la que
en la primera etapa es consideren les operacions de producció i en la segona es
plantegen les operacions d'acoblament.
Depenent de la configuració de la primera etapa s'han estudiat dos variants.
En la primera variant s'assumix que l'etapa de producció està composta per
sengles sistemes tipus flowshop en els que es fabriquen els components que
s'acoblen en la segona etapa (Distributed Assembly Permutation Flowshop
Scheduling Problem o DAPFSP). En la segona variant es considera un sistema
de màquines en paral.lel no relacionades (Distributed Parallel Machine and
Assembly Scheduling Problem o DPMASP). En ambdós variants s'optimitza
la data de finalització de l'últim treball seqüenciat (Cmax) i es contempla la
possibilitat que existisquen temps de canvi (setup) dependents de la seqüència
de treballs fabricada. També, en el cas DPMASP s'estudia la possibilitat de
prohibir o no l'ús de determinades màquines de l'etapa de producció.
S'han desenvolupat models matemàtics per a resoldre algunes de les variants
anteriors. Estos models s'han resolt per mitjà dels programes CPLEX
i GUROBI en aquells casos que ha sigut possible. Per a les instàncies en
què el model matemàtic no oferia una solució al problema s'han desenrotllat
heurístiques i metaheurísticas per a això. Tots els procediments anteriors han
sigut estudiats per a determinar el rendiment dels diferents algoritmes plantejats.
Per a això s'ha realitzat un exhaustiu estudi computacional en què s'han
aplicat tècniques ANOVA.
Els resultats obtinguts en la tesi permeten avançar en la comprensió del
comportament dels sistemes productius distribuïts amb acoblaments, definint
algoritmes que permeten obtindre bones solucions a este tipus de problemes
tan complexos que apareixen tantes vegades en la realitat industrial.<br>Hatami, S. (2016). The Distributed and Assembly Scheduling Problem [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/64072<br>TESIS
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OKUMA, Shigeru, Tatsuya SUZUKI, Fumiharu FUJIWARA, and Akio INABA. "Timed Petri Net Based Scheduling for Mechanical Assembly : Integration of Planning and Scheduling." Institute of Electronics, Information and Communication Engineers, 1998. http://hdl.handle.net/2237/14986.
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Dong, Yanan. "Optimal scheduling for SMT assembly line using neural networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0025/MQ35833.pdf.
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Burdett, Robert. "Sequencing and scheduling theory for mixed-model multi-stage assembly environment." Thesis, Queensland University of Technology, 2001.
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Hayes, Brian C. "Performance oriented scheduling with power constraints." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001073.
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Sikora, Celso Gustavo Stall. "Scheduling projects in operating systems: an application on assembly line balancing." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2859.
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Fundação Araucária; RENAULT; Seti<br>A Pesquisa Operacional investiga as (melhores) formas de se configurar e coordenar sistemas ou operações usando técnicas de otimização. Geralmente, a otimização de um sistema é modelado com base no estado final almejado. Porém, como atingir ou implementar tal estado final em sistemas é pouco retratado na literatura. Esta dissertaçãode mestrado propõe uma nova classe de problema de otimização: a programação das operações entre o estado inicial e o final de um sistema, o Problema de Implementação. A programação das operações é especialmente importante para linhas de montagem. A indústria automobilística é fortemente baseada em linhas de produção que podem ser usadas até 24 horas por dia. Assim, as oportunidades de intervenções para mudar ou otimizar o sistema produtivo são poucas. As condições de implementação aplicadas ao balanceamento de linhas produtivas são discutidas, e as características observadas resultam no proposto Problema de Implementação de Linhas de Montagem (PILM). Na dissertação, um guia de modelagem baseado em Programação Linear Inteira Mista (PLIM) é desenvolvido para a formulação de diversas variações do Problema de Implementação. As instruções de modelagem são usadas para desenvolver um conjunto de modelos PLIM para o Problema de Implementação de Linhas de Montagem. Para a obtenção de resultados, um conjunto de instâncias é proposto. Assim, uma análise de sensibilidade em função de cada um dos parâmetros formadores das instâncias é realizada. As formulações são comparadas, junto com as diferentes formas de apresentar e resolver o problema. Ademais, um método de decomposição é usado para resolver um problema industrial real. A modelagem mostrase correta para a divisão da implementação de mudanças em linhas de montagem. Os resultados mostram que a divisão do esforço de implementação resulta em apenas poucas mudanças a mais (cerca de 7% para os casos pequenos e médios) comparadas com a implementação em uma fase. A possibilidade de programar a implementação em etapas menores aumenta a aplicabilidade de projetos, que, de outra forma, requeririam grande paradas de produção.<br>Operations Research investigates the (best) ways to configure and coordinate systems or operations with optimization procedures. Usually, the optimization of a system is modeled based on the aimed final configuration. However, little is published about how to reach or implement such optimal configurations in the systems. This master thesis proposes a new class of optimization problem: a scheduling of operations between initial and final states of a system, the Implementation Problem. The scheduling of operations is especially important to assembly lines. The automotive industry strongly relies on production lines that can operate 24 hours a day. Thus, the intervention opportunities to change or optimize the production system are very few. The implementation conditions of balancing on assembly lines are discussed, and the observed characteristics result in the proposal of the Assembly Line Implementation Problem (ALIP). The master thesis proposes a Mixed-Integer Linear Programming (MILP) modeling guide for the formulation of several variations of Implementation Problems. The modeling instructions are used to develop a set of MILP models for the Assembly Line Implementation Problem. For the results, a dataset is proposed and a sensitivity analysis on each of the consistent parameters of the dataset is performed. The proposed formulations are compared, along with the different forms of presenting and solving the problem. Furthermore, a decomposition method is used to solve a real-world industrial problem. The modeling correctly represents the division of the implementation of changes in assembly lines. The results show that the division of the effort in multiple stages only need a few more changes (around 7\% for the small and medium cases) comparing to a straightforward implementation. The possibility of scheduling the implementation in smaller steps increases the applicability of projects that otherwise would require a large system's stoppage time.
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Das, Sanchoy K. "Selection of an optimal set of assembly part delivery dates in a stochastic assembly system." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45640.
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<p>The scheduling of material requirements at a factory to
maximize profits.or productivity is a difficult mathematical problem. The stochastic nature of most production setups introduces
additional complications as a result of the
uncertainty involved in vendor reliability and processing
times. But in developing the descriptive model for a system,
a true representation can only be attained if the variability
of these elements is considered.</p>
<p>Here we present the development of a normative model
based on a new type of descriptive model which considers the
element of stochasticity. The arrival time of an assembly
part from a vendor is considered to be a normally distributed
random variable. We attempt to optimize the system with regard to work-in-process inventory using a dynamic programming
algorithm in combination with a heuristic procedure. The decision
variable is the prescribed assembly part delivery
date. The model is particularly suitable for application in
low volume assembly lines, where products are manufactured
in discrete batches.</p><br>Master of Science
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Qin, Wei, and 秦威. "RFID-enabled real-time scheduling for assembly islands with fixed-position layouts." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46971993.
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Wong, Tse-chiu. "An evolutionary algorithm approach for assembly job shop scheduling with lot streaming technique." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39634462.
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Wong, Tse-chiu, and 黃資超. "An evolutionary algorithm approach for assembly job shop scheduling with lot streaming technique." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39634462.
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Miller, Anthonette. "Optimal production scheduling for vehicle assembly at Volkswagen of South Africa (Pty) Ltd." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/80788.
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Thesis (MBA)--Stellenbosch University, 2008.<br>ENGLISH ABSTRACT: Volkswagen of South Africa (Pty) Ltd. (VWSA) is part of the Volkswagen Group, which originated in Germany. VWSA’s production plant is situated in Uitenhage in the Eastern Cape and produces ± 100 000 cars per year with ± 5 800 employees. At the time of writing this report, VWSA had three platforms on which it produced the Citi Golf, Polo/Polo Classic and Golf 5/Jetta 5.
It takes on average four days to produce a vehicle, but up to 17 weeks lead time is required before production can start. This lead time is needed to procure, transport and receive the single parts from suppliers in South Africa, Europe and other countries. The time window required in order to manufacture a vehicle is therefore relatively long. For this reason it is important that VWSA’s production schedule is firstly planned properly and secondly optimised continuously and timely, as circumstances change and unforeseen conditions arise.
VWSA assemble vehicles “to stock” and not “to order”. This means that a production schedule is planned and executed, based on forecasted volumes and not on actual customer orders. The monthly production offline demand is received from marketing, which includes both the volume requirements for domestic and export units. Currently the production scheduling process of VWSA is performed manually in an Excel spreadsheet. This is a time consuming process that could be exposed to mistakes. Much iteration is performed manually in order to achieve the best solution.
The aim of this research report was to develop an optimisation model for production after the fixed lead time period in order to ensure finished products on time as per the local and export demand. VWSA requires a 52 week rolling production schedule, which should take all the various constraints into account. The objective of the production schedule is to determine shift patterns and production units per shift that will provide some consistency, by avoiding short time, overtime, plant closures, variations in production rates, etc. as far as possible. More importantly, the production schedule must optimise the use of resources and minimise costs.
A scheduling model was developed for each of the three model lines, making use of Mixed Integer Programming. The constraints and applicable costs were built into each individual model. Each model was solved with the use of Premium Solver Platform software, due to the fact that it has advance capabilities and includes a Nonlinear GRG Solver. Optimal solutions were found, satisfying all the various constraints, within seconds compared to the hours and days required for the current manual scheduling process.
A summary sheet was developed, combining the individual model line schedules for distribution and presentation purposes. This summarises the required production units per day, week and cumulative. In addition it includes the required export units that are first priority to be produced per week. To improve decision making, a column was included to indicate the quantity of units of each model type that must be produced during overtime. This model provides management with the information required to make decisions regarding detailed production scheduling.<br>AFRIKAANSE OPSOMMING: Volkswagen van Suid-Afrika (Pty) Ltd. (VWSA) is deel van die Volkswagen Groep, wat onstaan het in Duitsland. VWSA se produksie aanleg is geleë in Uitenhage in die Oos-Kaap en vervaardig ± 100 000 voertuie per jaar deur gebruik te maak van ± 5 800 werknemers. Ten tyde van die skryf van hierdie verslag het VWSA drie platforms gehad waarop dit die Citi Golf, Polo/Polo Classic en Golf 5/Jetta 5 vervaardig het.
Dit neem gemiddeld vier dae om ’n voertuig te vervaardig, maar kan tot 17 weke leityd benodig voordat produksie kan begin. Die leityd is nodig om enkel komponente van verskaffers in Suid-Afrika, Europa en ander lande te bestel, vervoer en te ontvang. Die tydperk wat benodig word om ’n voertuig te vervaardig is dus relatief lank. As gevolg van hierdie rede is dit belangrik dat VWSA se produksie skedule eerstens deeglik beplan word en tweedens aanhoudend en betyds ge-optimeer word soos omstandighede verander.
VWSA vervaardig voertuie vir voorraad en nie op bestellings nie. Dit beteken dat ’n produksieskedule beplan en uitgevoer word, gebasseer op vooruitgeskatte volumes en nie op konkrete bestellings van kliënte nie. Die maandlikse produksie aanvraag word ontvang vanaf die Bemarkings-departement en sluit beide binnelandse en uitvoer aanvraag in. Die produksie skedulering van VWSA word tans in ’n Excel sigblad verrig. Dit is ’n tydrowende proses wat blootgestel is aan moontlike foute. Baie iterasies word benodig om uiteindelik die mees gepaste oplossing te vind.
Die doel van hierdie navorsingsverslag was om ’n optimeringsmodel vir produksie na die vaste leityd tydperk te ontwikkel, met die doel om te verseker dat klaarprodukte betyds volgens die binnelandse en uitvoer aanvraag gelewer word. VWSA benodig ‘n 52 week rollende produksieskedule wat al die verskeie beperkings in ag neem. Die doel van die produksieskedule is om skofpatrone en volumes per skof te bepaal wat uiteindelik konsekwentheid verskaf deur korttyd, oortyd, aanlegsluitings, variasies in lynspoed, ens. te beperk. Meer belangrik, die produksieskedule moet die gebruik van bronne optimeer en kostes minimeer.
’n Skeduleringsmodel is ontwerp vir elkeen van die drie modellyne, deur gebruik te maak van Gemengde Heeltal Programmering. Die toepaslike beperkings en kostes is by elke individuële model ingebou. Elke model is opgelos deur gebruik te maak van “Premium Solver Platform” sagteware, as gevolg van die feit dat dit gevorderde vermoëens het asook “Nonlinear GRG Solver” insluit. Binne sekondes is optimale oplossings gevind, wat ook die beperkings bevredig, in teenstelling met die ure en dae wat benodig word vir die huidige skeduleringsproses.
‘n Opsommende blad is ontwikkel wat die individuële skedules saamvat vir verspreidings- en voordrag doeleindes. Dit bevat die beplande produksievolumes per dag, week en kumulatief. Addisioneel bevat dit ook die vereiste uitvoervolumes per week wat eerste prioriteit geniet. Om besluitneming te verbeter is ‘n kolom ingesluit wat aandui hoeveel eenhede van elke model tipe word benodig gedurende oortydproduksie. Die model verskaf aan bestuur die inligting wat benodig word om detail besluite oor produksieskedulerings te neem.
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Lü, Haili, and 吕海利. "A comparative study of assembly job shop scheduling using simulation, heuristics and meta-heuristics." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47029018.
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Sedore, Blake William Clark. "Assembly lead time reduction in a semiconductor capital equipment plant through constraint based scheduling." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93851.
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Thesis: M. Eng. in Manufacturing, Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (page 80).<br>The assembly protocols for a semiconductor capital equipment machine were analyzed for potential lead time reduction. The objective of this study was to determine the minimum assembly lead time for the machine based on the constraints of design, space, and labor availability. An assembly requires the completion of a set of procedures that each contains assembly tasks. Precedence relationships between tasks indicate for each procedure what other tasks must be completed before it can start. Each procedure was assumed to have constant resource requirements throughout its duration. The Critical Path Method (CPM) was used to identify 13 procedures on the critical path, based on design and space constraints. A preliminary build schedule was developed that prioritized critical path procedures. A trial of this build schedule achieved an assembly lead time of 39 hours, resulting in a 70% reduction from the current average of 5.5 days. This trial was also accomplished with 76% of the average labor hours for assembly. A production build schedule with a lead time of 43 hours was developed based on the trial results. This schedule allows for production rates of up to 5 machines per week to be achieved with the current shift structure of the company, without the incurrence of overtime. A critical path drag analysis identified critical procedures with the highest potential for lead time reduction. The highest drag of a critical path item was 260 minutes, accounting for 10% of the assembly lead time.<br>by Blake William Clark Sedore.<br>M. Eng. in Manufacturing
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Pereira, Mário Tonizza. "Proposta de um modelo de simulação computacional para a programação de operações em sistemas assembly shop." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3148/tde-06052009-012159/.
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Esta dissertação estuda o problema da programação de operações em sistemas job shop de manufatura onde itens com estruturas de materiais são produzidos a partir de componentes fabricados e montados. Tais sistemas são denominados assembly shops. O caso geral do problema de programação de operações em sistemas job shop, no qual não existem restrições quanto ao número de operações a serem programadas nem quanto ao número de máquinas a serem alocadas, é considerado, até o presente momento, intratável do ponto de vista computacional devido à explosão combinatória inerente ao processo de programação, independente da escolha do critério de desempenho. Isto significa dizer que não existe nenhum método eficiente de programação que resolva globalmente instâncias de porte real do problema dentro de um tempo computacional considerado satisfatório. Devido a este fato, nas últimas três décadas, diversos métodos aproximados e heurísticos foram propostos e avaliados para o problema. Nesta pesquisa, é proposto e avaliado um novo método heurístico de programação. Fundamentado na pressuposição de que a melhoria na sincronização de operações de montagem em sistemas assembly shop leva ao melhor atendimento de datas de entrega de pedidos, o método implementa duas abordagens de programação: uma abordagem backward que satisfaz completamente as datas de entrega e outra forward que satisfaz completamente a restrição de capacidade de máquina. Ambas trabalham iterativamente dentro de dois modelos de simulação do sistema de produção um determinístico e outro probabilístico na busca pela melhoria da sincronização das operações e no atendimento das datas de entrega. Os resultados experimentais demonstraram que o desempenho do novo método foi em média melhor que os dos métodos não iterativos (regras) avaliados e tão bom quanto o desempenho do melhor método não iterativo (regra) testado.<br>This dissertation studies the problem of scheduling operations in manufacturing job shop environments where items with bill of materials are made of many fabricated and assembled components. Such systems are known as assembly shops. The general job shop scheduling problem, which no restrictions exist neither for the number of operations to be scheduled nor for the number of machines to be allocated, is considered at the present date intractable from the computational point of view, whatever the performance criterion used, due to the combinatorial explosion inherent to the scheduling process. It means that there is not an efficient computational method that solves globally real size instances of the problem within a satisfactory period of time. Due to this fact, in the last three decades several approximated and heuristic methods were created and evaluated for the problem. This research proposes and evaluate a new heuristic method which is based on the assumption that the improvement in operations synchronization at the assembly stations brings forth better achievement of due dates. The method implements two scheduling approaches: a backward approach satisfying due date completely and a forward approach satisfying capacity restriction completely. The two approaches work iteratively within two different simulation models of the production system one deterministic e other probabilistic in searching for operations synchronization improvement and due date achievement. The experimental results have shown the new method was better than the single-pass methods (rules) on average and as good as the better single-pass method (rule) tested.
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Saboo, Surendra. "Estimating correlations between certain operation finishing times to approximate the transient performance of stochastic assembly systems /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487267546982395.
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Cheng, Ming. "Lot streaming in a two-stage assembly system and a hybrid flow shop." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77197.
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In this dissertation, we investigate the use of lot streaming in a two-stage assembly system and a two-stage hybrid flow shop in order to improve system performance. Lot streaming accelerates the flow of a production lot through a production process by splitting it into sublots, and then, processing these sublots in an overlapping fashion over the machines, thereby reducing work-in-process and cycle-time. Traditionally, lot streaming has been applied to problems in various flow shop machine configurations. It has also been applied to machine environments of job shop, open shop, and parallel machines. Its application to assembly system is relatively new.
The two-stage assembly system that we consider consists of multiple suppliers at Stage 1 with each supplier producing one type of a subassembly (or a component), and one or more assembly locations at Stage 2, where the subassemblies are then put together. Lot-attached and sublot-attached setup time and cost are encountered on the machines at both the stages, and sublot-attached time and cost are encountered for the transfer of sublots from Stage 1 to Stage 2. Mass customization is an example of such a system in which the final assembly of a product is postponed to capture specific customer demands. Dell Computer constitutes a real-life example of this system. A customer picks his/her computer processor, memory, storage, and other equipment, on Dell's web site. Dell's supply chain is configured to obtain subassemblies from suppliers (stage 1), and then, to assemble the requisite systems in different market areas (stage 2). This enables a reduction in operating cost while improving responsiveness to customers. The problem that we address is as follows: Given a maximum number of sublots of each lot, determine the number of sublots to use (assuming equal sublot sizes), and also, the sequence in which to process the lots, in order to minimize two criteria, namely, makespan, total cost. We propose two column generation-based methods that rely on different decomposition schemes. The results of our computational investigation conducted by using randomly generated data sets reveal that the proposed column generation methods obtain solutions in a few seconds of CPU time while the direct solution by CPLEX of a mixed integer programming model of the problem requires much larger CPU times.
For the hybrid flow shop lot streaming problem, the machine configuration that we consider consists of one machine at Stage 1 and two machines at Stage 2 (designated as 1+2 system). A single lot is to be processed in the system, and the objective is to minimize the makespan. A removal time is associated with each sublot at Stage 1. We present a mixed integer programming model for this problem to determine optimal number of sublots and sublot sizes. First, we consider the case of a given number of sublots for which we develop closed-form expressions to obtain optimal, continuous sublot sizes. Then, we consider determination of optimal number of sublots in addition to their sizes. We develop an upper bound on optimal number of sublots, and use a simple search procedure in conjunction with the closed-form expressions for sublot sizes to obtain an optimal solution. We also consider the problem of determining integer sublot sizes, and propose a heuristic method that directly solves the mixed integer programming model after having fixed values of appropriate variables. The results of our numerical experimentation reveal the efficacy of the proposed method to obtain optimal, continuous sublot sizes, and also, that of the proposed heuristic method to obtain integer sublot sizes, which are within 0.2% of optimal solutions for the testbed of data used, each obtained within a few seconds of CPU time.
The last problem that we address is an extension of the single-lot lot streaming problem for a $1+2$ hybrid flow shop considered above to the case of multiple lots, where each lot contains items of a unique product type. We consider two objectives: minimize makespan, and minimize the sum of the completion times for all the lots. The consideration of multiple lots introduces a complicating issue of sequencing the lots. We use the results derived for the single-lot problem and develop effective heuristic methods for this problem. The results of our computational investigation on the use of different heuristic methods reveal their efficacy in solving this problem.<br>Ph. D.
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Carroll, Robert. "The pure assembly multi-stage production-scheduling problem : a mathematical treatment and the creation of a new algorithm." Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401135.
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Meng, Kai M. Eng Massachusetts Institute of Technology. "Reduce cycle time and work in process in a medical device factory : scheduling policies for needle assembly machine." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42328.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.<br>Includes bibliographical references (p. 58).<br>Many manufacturing firms have improved their operations by implementing a work-in-process (WIP) limiting control strategy. This project explores the application of this concept to limit WIP and reduce cycle time for the Becton, Dickinson and Company's manufacturing facility in Tuas, Singapore. BD's Eclipse Safety Needle production line is facing increasing pressure to reduce its high WIP and long cycle times. With the forecast of increasing demand, the current production control practice will sooner or later push the shop floor space to a limit. We divided the overall system into three manageable sub-systems and analyzed different strategies for each. At Needle Assembly machine (AN) and downstream, we can achieve significant reduction in cycle time and work in process by eliminating the unnecessary early start of production and extra delay caused by the current planning method, and by reducing the transfer batch sizes. In this paper, we refine further these approaches to AN and packaging machines with consideration of a mixed dispatching rule and a CONWIP release rule. The mixed dispatching rule reduces WIP level of the system by enhancing the total throughput of the four production routes after the bottleneck (AN machine). The CONWIP release rule further reduces WIP by controlling the total amount of inventory in the system. With these four proposed strategies, we can have a pure pull system within AN and downstream machines and achieve significant reduction in cycle time and WIP.<br>by Kai Meng.<br>M.Eng.
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Singh, Sanchit. "Modeling, Analysis, and Algorithmic Development of Some Scheduling and Logistics Problems Arising in Biomass Supply Chain, Hybrid Flow Shops, and Assembly Job Shops." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/91466.
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In this work, we address a variety of problems with applications to `ethanol production from biomass', `agile manufacturing' and `mass customization' domains. Our motivation stems from the potential use of biomass as an alternative to non-renewable fuels, the prevalence of `flexible manufacturing systems', and the popularity of `mass customization' in today's highly competitive markets. Production scheduling and design and optimization of logistics network mark the underlying topics of our work. In particular, we address three problems, Biomass Logistics Problem, Hybrid Flow Shop Scheduling Problem, and Stochastic Demand Assembly Job Scheduling Problem.
The Biomass Logistics Problem is a strategic cost analysis for setup and operation of a biomass supply chain network that is aimed at the production of ethanol from switchgrass. We discuss the structural components and operations for such a network. We incorporate real-life GIS data of a geographical region in a model that captures this problem. Consequently, we develop and demonstrate the effectiveness of a `Nested Benders' based algorithm for an efficient solution to this problem.
The Hybrid Flow Shop Scheduling Problem concerns with production scheduling of a lot over a two-stage hybrid flow shop configuration of machines, and is often encountered in `flexible manufacturing systems'. We incorporate the use of `lot-streaming' in order to minimize the makespan value. Although a general case of this problem is NP-hard, we develop a pseudo-polynomial time algorithm for a special case of this problem when the sublot sizes are treated to be continuous. The case of discrete sublot sizes is also discussed for which we develop a branch-and-bound-based method and experimentally demonstrate its effectiveness in obtaining a near-optimal solution.
The Stochastic Demand Assembly Job Scheduling Problem deals with the scheduling of a set of products in a production setting where manufacturers seek to fulfill multiple objectives such as `economy of scale' together with achieving the flexibility to produce a variety of products for their customers while minimizing delivery lead times. We design a novel methodology that is geared towards these objectives and propose a Lagrangian relaxation-based algorithm for efficient computation.<br>Doctor of Philosophy<br>In this work, we organize our research efforts in three broad areas - Biomass Supply Chain, Hybrid Flow Shop, and Assembly Job Shop, which are separate in terms of their application but connected by scheduling and logistics as the underlying functions. For each of them, we formulate the problem statement and identify the challenges and opportunities from the viewpoint of mathematical decision making. We use some of the well known results from the theory of optimization and linear algebra to design effective algorithms in solving these specific problems within a reasonable time limit. Even though the emphasis is on conducting an algorithmic analysis of the proposed solution methods and in solving the problems analytically, we strive to capture all the relevant and practical features of the problems during formulation of each of the problem statement, thereby maintaining their applicability. The Biomass Supply Chain pertains to the production of fuel grade ethanol from naturally occurring biomass in the form of switchgrass. Such a system requires establishment of a supply chain and logistics network that connects the production fields at its source, the intermediate points for temporary storage of the biomass, and bio-energy plant and refinery at its end for conversion of the cellulosic content in the biomass to crude oil and ethanol, respectively. We define the components and operations necessary for functioning of such a supply chain. The Biomass Logistics Problem that we address is a strategic cost analysis for setup and operation of such a biomass supply chain network. We focus our attention to a region in South Central Virginia and use the detailed geographic map data to obtain land use pattern in the region. We conduct survey of existing literature to obtain various transportation related cost factors and costs associated with the use of equipment. Our ultimate aim here is to understand the feasibility of running a biomass supply chain in the region of interest from an economic standpoint. As such, we represent the Biomass Logistics Problem with a cost-based optimization model and solve it in a series of smaller problems. A Hybrid Flow Shop (HFS) is a configuration of machines that is often encountered in the flexible manufacturing systems, wherein a particular station of machines can execute processing of jobs/tasks simultaneously. In our work, we approach a specific type of HFS, with a single machine at the first stage and multiple identical machines at the second stage. A batch or lot of jobs/items is considered for scheduling over such an HFS. Depending upon the area of application, such a batch is either allowed to be split into continuous sections or restricted to be split in discrete sizes only. The objective is to minimize the completion time of the last job on its assigned machine at the second stage. We call this problem, Hybrid Flow Shop Scheduling Problem, which is known to be a hard problem in literature. We aim to derive the results which will reduce the complexity of this problem, and develop both exact as well as heuristic methods in order to obtain near-optimal solution to this problem. An Assembly Job Shop is a variant of the classical Job Shop which considers scheduling a set of assembly operations over a set of assembly machines. Each operation can only be started once all the other operations in its precedence relationship are completed. Assembly Job Shop are at the core of some of the highly competitive manufacturing facilities that are principled on the philosophy of Mass Customization. Assuming an inherent nature of demand uncertainty, this philosophy aims to achieve ‘economy of scale’ together with flexibility to produce a variety of products for the customers while minimizing the delivery lead times simultaneously. We incorporate some of these challenges in a concise framework of production scheduling and call this problem as Stochastic Demand Assembly Job Scheduling Problem. We design a novel methodology that is geared towards achieving the set objectives and propose an effective algorithm for efficient computation.
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Yao, Liming. "Modeling, Analysis and Solution Approaches for Some Optimization Problems: High Multiplicity Asymmetric Traveling Salesman, Primary Pharmaceutical Manufacturing Scheduling, and Lot Streaming in an Assembly System." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/27961.
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This dissertation is devoted to the modeling, analysis and development of solution approaches for some optimization-related problems encountered in industrial and manufacturing settings. We begin by introducing a special type of traveling salesman problem called "High Multiplicity Asymmetric Traveling Salesman Problem" (HMATSP). We propose a new formulation for this problem, which embraces a flow-based subtour elimination structure, and establish its validity for this problem. The model is, then, incorporated as a substructure in our formulation for a lot-sizing problem involving parallel machines and sequence-dependent setup costs, also known as the "Chesapeake Problem". Computational results are presented to demonstrate the efficacy of our modeling approach for both the generic HMATSP and its application within the context of the Chesapeake Problem.
Next, we investigate an integrated lot-sizing and scheduling problem that is encountered in the primary manufacturing facility of pharmaceutical manufacturing. This problem entails determination of production lot sizes of multiple products and sequence in which to process the products on machines, which can process lots (batches) of a fixed size (due to limited capacity of containers) in the presence of sequence-dependent setup times/costs. We approach this problem via a two-stage optimization procedure. The lot-sizing decision is considered at stage 1 followed by the sequencing of production lots at stage 2. Our aim for the stage 1 problem is to allocate batches of products to time-periods in order to minimize the sum of the inventory and backordering costs subject to the available capacity in each period. The consideration of batches of final products, in addition to those for intermediate products, which comprise a final product, further complicates the lot-sizing problem. The objective for the stage 2 problem is to minimize sequence-dependent setup costs. We present a novel unifying model and a column generation-based optimization approach for this class of lot-sizing and sequencing problems. Computational experience is first provided by using randomly generated data sets to test the performances of several variants of our proposed approach. The efficacy of the best of these variants is further demonstrated by applying it to the real-life data collected with the collaboration of a pharmaceutical manufacturing company.
Then, we address a single-lot, lot streaming problem for a two-stage assembly system. This assembly system is different from the traditional flow shop configuration. It consists of m parallel subassembly machines at stage 1, each of which is devoted to the production of a component. A single assembly machine at stage 2, then, assembles products after components (one each from the subassembly machines at the first stage) have been completed. Lot-detached setups are encountered on the machines at the first and second stages. Given a fixed number of transfer batches (or sublots) from each of the subassembly machines at stage 1 to the assembly machine at stage 2, our problem is to find sublot sizes so as to minimize the makespan. We develop optimality conditions to determine sublot sizes for the general problem, and present polynomial-time algorithms to determine optimal sublot sizes for the assembly system with two and three subassembly machines at stage 1.
Finally, we extend the above single-lot, lot streaming problem for the two-stage assembly system to multiple lots, but still, for the objective of minimizing the makespan. Due to the presence of multiple lots, we need to address the issue of the sequencing of the lots along with lot-splitting, a fact which adds complexity to the problem. Some results derived for the single-lot version of this problem have successfully been generalized for this case. We develop a branch-and-bound-based methodology for this problem. It relies on effective lower bounds and dominance properties, which are also derived. Finally, we present results of computational experimentation to demonstrate the effectiveness of our branch-and-bound-based methodology. Because of the tightness of our upper and lower bounds, a vast majority of the problems can be solved to optimality at root node itself, while for others, the average gap between the upper and lower bounds computed at node zero is within 0.0001%. For a majority of these problems, our dominance properties, then, effectively truncate the branch-and-bound tree, and obtain optimal solution within 500 seconds.<br>Ph. D.
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Dai, Bin. "The evaluation of a production scheduling heuristic for production lines with changeover costs and dependent parallel processors." Ohio : Ohio University, 1990. http://www.ohiolink.edu/etd/view.cgi?ohiou1183488445.
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Bastos, Karen Juliana Weigner de. "Uma abordagem matheurística para o problema de sequenciamento de tarefas e balanceamento de linhas de montagem de modelo único com Tempos de Setup dependentes da sequência." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/127224.
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O Problema de Balanceamento e Sequenciamento de Linhas de Montagem com Tempos de Setup dependentes da Sequência (SUALBSP, em inglês Setup Assembly Line Balancing and Scheduling) envolve a atribuição de tarefas às estações de trabalho e o sequenciamento destas tarefas dentro da estação à qual foi atribuída. Trabalhos anteriores propuseram soluções heurísticas com excelentes resultados, porém o uso de métodos exatos, por meio de algum resolvedor de Programação Inteira Mista, tem apresentado desempenhos decepcionantes, pois contém um subproblema NP-hard em todas as estações. Enquanto o modelo de Scholl, Boysen e Fliedner (2013) minimiza prioritariamente o número de estações, o modelo proposto neste trabalho parte da premissa que este é um dado definido. A partir de uma estimativa inicial de número de estações, processa-se o modelo com o objetivo de distribuir as tarefas e minimizar o tempo total de estação, que é o segundo objetivo do modelo original. Se este processamento for infactível, incrementa-se o número de estações em uma unidade e reprocessa-se o modelo até se encontrar um resultado factível. Experimentos computacionais em 101 instâncias de dados confirmam o bom desempenho da abordagem proposta, sem qualquer prejuízo à qualidade da solução. Portanto, os resultados apresentados demonstram que há espaço para estudos futuros a partir do uso de matheurísticas.<br>The Setup Assembly Line Balancing and Scheduling Problem (SUALBSP) involves the assigning of tasks to workstations and the sequencing of these tasks within the station to which they are assigned. Previous work has proposed heuristic solutions with excellent results, but the use of exact methods, by some Mixed-Integer Programming solver, has shown disappointing performance, because it contains an NP-hard sub problems in every station. While the model proposed by Scholl, Boysen and Fliedner (2013) primarily minimizes the numbers of stations, our model assumes it as a parameter. From an initial estimate of the number of stations, we process the model for allocating tasks and minimize station times, which is the second objective of the original model. If this processing is infeasible, we increase the number of stations by one unit and we reprocess the model to find a feasible result. Computational experiments in 101 instances of data set confirm the good performance of the proposed approach, without harming the quality of the solution. Therefore, the results show that there are opportunities for future studies based on the use of matheuristics.
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Han, Yong-Hee. "Dynamic Sequencing of Jobs on Conveyor Systems for Minimizing Changeovers." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4877.
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This research investigates the problem of constrained sequencing of a set of jobs on a conveyor system with the objective of minimizing setup cost. A setup cost is associated with extra material, labor, or energy required due to the change of attributes in consecutive jobs at processing stations. A finite set of attributes is considered in this research. Sequencing is constrained by the availability of two elements ??orage buffers and conveyor junctions. The problem is motivated by the paint purge reduction problem at a major U.S. automotive manufacturer. First, a diverging junction with a sequence-independent setup cost and predefined attributes is modeled as an assignment problem and this model is extended by relaxing the initial assumptions in various ways. We also model the constrained sequencing problem with an off-line buffer and develop heuristics for efficiently getting a good quality solution by exploiting the special problem structure. Finally, we conduct sensitivity analysis using numerical experiments, explain the case study, and discuss the use of the simulation model as a supplementary tool for analyzing the constrained sequencing problem.
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Silva, Bruno Jensen Virginio da. "Programação de montagens em gabaritos com restrições de adjacência na indústria aeronáutica." Universidade Federal de São Carlos, 2010. https://repositorio.ufscar.br/handle/ufscar/3648.
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Previous issue date: 2010-12-03<br>Financiadora de Estudos e Projetos<br>This work deals with a production scheduling problem that appears in the aeronautics industry, involving special structures called assembly fixtures, composed of several workstations in parallel to assemble parts of the aircrafts. Tasks should be scheduled to be performed in these workstations in order to minimize the quantity of manpower needed to do the assembly and determine the production capacity of the assembly fixture, which means minimizing the makespan (the total time needed to finish the tasks). However, in addition to the usual constraints such as due dates and precedence among tasks, there are also constraints that prevent two tasks to be performed at the same time in two adjacent workstations on the assembly fixture. The assembly and the teams who work there are in continuous improvement of assembling processes, according to the cumulative production increases and the learning curve is traversed. The learning curve was divided in four stages with specific characteristics in each. Mixed integer linear programming models are proposed to represent the production scheduling problem of each stage, based on practical cases studies of assembly fixtures scheduling in an aeronautics company. Those models are solved using a modeling language and optimization software. The solutions are analyzed and compared and based on then, it is evaluated how the learning curve affects the airplane production over time and it is shown, in the results, that there exists potential of improvement in the use of assembling resources, using production scheduling and levelling the resources.<br>Este trabalho aborda um problema de programação da produção que ocorre na indústria aeronáutica, envolvendo estruturas especiais de montagem chamadas gabaritos, compostas de diversos postos de trabalho em paralelo para montar partes das aeronaves. Tarefas devem ser programadas para serem executadas nestes postos de trabalho de maneira a minimizar a quantidade total de mão de obra necessária para realizar a montagem em questão e determinar a capacidade de produção do gabarito, ou seja, minimizar o makespan (tempo total para executar as tarefas). Porém, além das restrições usuais, como prazos de entrega das tarefas e precedências entre as tarefas, existem também restrições que impedem que duas tarefas possam ser executadas ao mesmo tempo em dois postos de trabalho adjacentes no gabarito. A montagem e as equipes que nela trabalham estão em melhoria contínua dos processos de montagem, conforme a produção acumulada aumenta e a curva de aprendizagem é percorrida. A curva de aprendizagem foi dividida em quatro fases com características específicas em cada uma. Propõem-se modelos de programação linear inteira mista para representar o problema de programação em cada uma das fases, com base em estudos de casos práticos de programação de gabaritos de montagem de uma empresa aeronáutica. Estes modelos são resolvidos utilizando-se uma linguagem de modelagem e um software de otimização. As soluções encontradas são analisadas e comparadas e com base nelas, avalia-se como a curva de aprendizagem afeta a produção de aviões ao longo do tempo e demonstra-se que existe potencial de melhoria no uso dos recursos de montagem, utilizando programação da produção e nivelamento dos recursos.
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McClellan, Jack J. "The Benefit of Using Simulation to Improve The Implementation of Lean Manufacturing Case Study: Quick Changeovers to Allow Level Loading of The Assembly Line." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd558.pdf.
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Vladimir, Marinković. "Прилог аутоматској паралелизацији секвенцијалног машинског кода". Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2018. https://www.cris.uns.ac.rs/record.jsf?recordId=107635&source=NDLTD&language=en.
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Докторска теза анализира подршку за вишејезгарне и многојезгарне системе у циљу повећања искоришћења њихове снаге. Предмет истраживања је проналажење решења које би без уплитања програмера (аутоматски) паралелизовало постојеће секвенцијалне програме на бинарном нивоу који се извршавају на једном језгру (или процесору). Резултат истраживања је израда решења и алата за паралелизацију секвенцијалног машинког кода, који самостално стварају програме који се извршавају паралелно на више језгара вишејезгарног процесора, и тиме постижу балансирано оптерећење процесора. Основни циљ је добијање убрзања извршења програмског кода на вишејезгарном процесору ради омогућавања рада у реланом времену за задата ограничења. Добијено решење би се могло искористити и за смањење потрошње смањивањем радног такта процесора уз задржавање полазног времена извршења програма.<br>Doktorska teza analizira podršku za višejezgarne i mnogojezgarne sisteme u cilju povećanja iskorišćenja njihove snage. Predmet istraživanja je pronalaženje rešenja koje bi bez uplitanja programera (automatski) paralelizovalo postojeće sekvencijalne programe na binarnom nivou koji se izvršavaju na jednom jezgru (ili procesoru). Rezultat istraživanja je izrada rešenja i alata za paralelizaciju sekvencijalnog mašinkog koda, koji samostalno stvaraju programe koji se izvršavaju paralelno na više jezgara višejezgarnog procesora, i time postižu balansirano opterećenje procesora. Osnovni cilj je dobijanje ubrzanja izvršenja programskog koda na višejezgarnom procesoru radi omogućavanja rada u relanom vremenu za zadata ograničenja. Dobijeno rešenje bi se moglo iskoristiti i za smanjenje potrošnje smanjivanjem radnog takta procesora uz zadržavanje polaznog vremena izvršenja programa.<br>PhD thesis analyzes a support for multicore and manycore systems in termsof better processing power utilization. Purpose of this study is finding asolution for automatic parallelization of existing sequential code whichexecutes on single core (or processor), at the binary level. The researchintents to develop a solution and tools for parallelization of the sequentialmachine code, which can create a program running simultaneously on all thecores of the multi-core processor, and for achieving optimal load-balancing.The primary goal is obtaining execution speedup of the program running onthe multicore processor, for meeting real-time processing constraints. Givensolution could be also used for energy saving, by lowering system clock andkeeping program execution runtime.
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Alexa, Martin. "Stavebně technologický projekt mateřské školy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-371896.
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This thesis handles the construction and technological project of nursery school in the Brno. It deals with technical reports, technological methods of construction. The report contains technical reporst of building equipment, schedule, design of mechanical assembly, inspection and health and safety at work.
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Sigmund, Martin. "Stavebně technologický projekt haly teleskopických krytů - HESTEGO a.s." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227862.
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The content of this thesis titled "Construction and technological project of the telescopic covers hall" is building - technological solution of building together with technical, time, financial, safety, qualitative, fire and legislative solutions of selected building.
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Halouzka, Jakub. "Rekreační objekt Kouty nad Desnou - stavebně technologický projekt." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226487.
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In this thesis, technological project of building an apartment house in Kouty Desnou is presented. The thesis will include drawings of the site facilities, budget, three technological regulations to solved stages, building technology study, scheduling, resource and material balance, control and test plan and safety.
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Homolová, Sandra. "Stavebně technologický projekt lékárny v areálu FN Olomouc." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227234.
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The subject of my thesis is the technology of pharmacy building in the area of University Hospital Olomouc. I deal especially with foundation of the building on bored piles and cast-in-place concrete structures. The work includes engineering reports, time scheduling of the building, itemized budget, site equipment, health and safety plan, two technological prescriptions and two inspection and test plans. The last chapter is devoted to the contract for work.
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LIU, RONG-ZONG, and 劉榮宗. "Assembly scheduling in a two-stage, machining-assembly system." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/96277738707120462276.
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BAI, SHU-XIAN, and 白述賢. "Job shop scheduling with assembly constraint." Thesis, 1986. http://ndltd.ncl.edu.tw/handle/13573763966912122859.
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"Scheduling the assembly process with uncertain material arrivals." 1998. http://library.cuhk.edu.hk/record=b5889667.
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by Cheung Chit-Cheung, Gavin.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.<br>Includes bibliographical references (leaves 75-77).<br>Abstract also in Chinese.<br>Abstract --- p.i<br>Acknowledgment --- p.ii<br>Chapter 1 --- Introduction --- p.1<br>Chapter 1.1 --- Motivation --- p.2<br>Chapter 1.2 --- Problem Description --- p.5<br>Chapter 1.3 --- Contributions --- p.6<br>Chapter 1.4 --- Thesis Organization --- p.6<br>Chapter 2 --- Problem Formulation and Solution Approaches --- p.8<br>Chapter 2.1 --- Mathematical Modeling --- p.8<br>Chapter 2.2 --- Transformation of Problem --- p.11<br>Chapter 2.3 --- Problem Analysis --- p.12<br>Chapter 2.3.1 --- Optimality Criteria --- p.13<br>Chapter 2.3.2 --- Heuristic Solutions --- p.15<br>Chapter 2.4 --- Literatures Review on Single-Machine Scheduling --- p.18<br>Chapter 3 --- Discussion of Some Special Cases --- p.21<br>Chapter 3.1 --- Two Operations --- p.22<br>Chapter 3.2 --- Identical Distributions --- p.24<br>Chapter 3.2.1 --- Error Bound of LPTF - Maximum Distribution Approach --- p.27<br>Chapter 3.3 --- Large Initial Time and Special Processing Times Structure --- p.29<br>Chapter 3.3.1 --- Application of SVF to Exponential Distribution --- p.34<br>Chapter 3.3.2 --- Error Bound of SVF 一 Switching Processing Times Approach --- p.37<br>Chapter 3.3.3 --- Extended Error Bound Analysis --- p.41<br>Chapter 4 --- Heuristics to Solve the General Problems --- p.47<br>Chapter 4.1 --- Level 1 - PIPF and LPTF Rules --- p.48<br>Chapter 4.2 --- Level 2 - Adjacent Pair wise Interchange --- p.51<br>Chapter 4.3 --- Computational Complexity --- p.53<br>Chapter 5 --- Experimental Results --- p.54<br>Chapter 5.1 --- Design of Experiments --- p.54<br>Chapter 5.1.1 --- Design of Problem Parameters --- p.55<br>Chapter 5.1.2 --- Evaluation Methods --- p.57<br>Chapter 5.2 --- Results Analysis --- p.59<br>Chapter 5.2.1 --- Evaluation for Problems with Small Size --- p.60<br>Chapter 5.2.2 --- Evaluation for Problems with Large Size --- p.63<br>Chapter 6 --- Conclusion --- p.67<br>Chapter 6.1 --- Summary --- p.67<br>Chapter 6.2 --- Future Extension --- p.68<br>Appendix --- p.69<br>Chapter A --- Crossing Point of Normal Density Functions --- p.69<br>Chapter B --- Probaiblity Distributions --- p.73<br>Chapter B.1 --- Uniform Distribution --- p.73<br>Chapter B.2 --- Exponential Distribution --- p.74<br>Chapter B.3 --- Normal Distribution --- p.74<br>Bibliography --- p.75
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Hsu, Ham-Huah, and 徐漢華. "Fully Automated Robotic Assembly Cell :Scheduling and Simulation." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/77397837198740083920.
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碩士<br>國立臺灣大學<br>資訊工程研究所<br>82<br>As the fully automated assembly system in multi-robot enviro-
nment played an important role, the scheduling problem became
more and more important than before. Hence, the complexity of
this kind of system was growing, so that modeling it for
schedu- ling was became more difficult. Here, we proposed a new
methodo- logy for modeling this kind of assembly system. It is
more intui- tive that representation of this kind of assembly
system used the ruler-based knowledge, which are generated
according to the assembly AND/OR graph. This method of assembly
rules approaching is used for assembly scheduling. Based on
those rules, the assem- bly scheduling deduces all of the
possible assembly tasks. The integration of a scheduling method
and a simulation envi- ronment is our another topic. Here, the
experiment of a multi- robot assembly system was proposed.
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Wu, Tung-chun, and 吳統鈞. "Scheduling Mixed-Model Assembly Lines by Neural Network." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/58401167485938672989.
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碩士<br>國立交通大學<br>管理科學研究所<br>82<br>In this thesis, we first discuss why two 'goal chasing'
heuristics developed at Toyota is not optimum by literature
survey. GCI and GCII focus on constant component usage in each
stage in order to achieve the goal of minimum TSD. But these
two algorithms do not consider the effect of deviation on
future stage of this stage current decision; therefore, GCI and
GCII is myoptic and is not optimum. Hopfield and Tank (1985)
showed that some combinatorial optimization problems can be
solved by using artificial neural network systems. Because the
scheduling problem is also combinatorial optimization problems,
we can solve the problem of scheduling mixed-model assembly
lines by Hopfield Net. In this thesis, we construct two neural
networks, combine them to solve the problem of scheduling mixed-
model assembly lines, and thus get a set of synaptic
interconnection strength and self bias input. In this thesis,
we use Gaussian machine model to avoid problems of being
trapped in a local optimum solution. We also adopt
asynchronous transition mode for the purpose of reducing
oscillatory behaviour. In the numerical experiment, we find a
renewed model which can achieve much better schedule results,
and this may be considered a little tiny contribution. Finally
we prove that the problem of scheduling mixed-model assembly
lines can be solved by Hopfield Net via the numerical
experiment, and Hopfield Net gets even better results than
other scheduling algorithms. Accordingly, we have come to a
conclusion that the synaptic interconnection strength and self
bias input developed by the author are correct. This is the
major contribution of the thesis.
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LIN, CHUNG-HUA, and 林宗華. "Batch scheduling problems for two-stage assembly shop." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/35601029398409794068.
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博士<br>國立臺灣科技大學<br>工業管理系<br>100<br>In this thesis, we consider the batch scheduling problems for two-stage assembly shop, which are frequently encountered in the machinery manufacturing. In the first stage, a fixed number of jobs are assembled on a batch machine with a common processing time. Then the assembled jobs are moved to the second stage to perform system integration with different processing times on a discrete machine. In this thesis, two cases are considered: (1) Batch scheduling for an assembly line, and (2) Batch scheduling for assembly islands. In Case (1), all jobs in a machinery factory share a common assembly line. A constant batch setup time is needed to form a batch at the first stage and fixed family setup times are required on both stages when starting the processing of a new family or switching to a job in a different family. The objective is to find a schedule that minimizes the weighted sum of makespan, total completion time and total tardiness. In Case (2), a machinery factory is equipped with fixed-position assembly islands where each job must remain in an assembly island during its entire processing. A family batch setup time is needed to form a batch at the first stage and a fixed removal time is incurred when a finished job is moved from an assembly island to a temporary storage area if the payment has not been made. The objective is to minimize the total completion time.
Since the two considered problems have been proved to be NP-hard, we develop Mixed Integer Programming (MIP) models to find the optimal solutions for small-size problem and propose some heuristic methods for each large-size problem. We also conduct computational experiments to compare MIP models with the corresponding heuristic methods. The computational results show that the proposed methods (FBFS and P-FBFS) outperform the current scheduling methods and can be applied to resolve real-world problems similar to those in this thesis.
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Long, Tzao Sheng, and 龍早生. "A study of job shop scheduling with assembly operations." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/30829358706908550874.
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Lin, Ming-Hung, and 林銘宏. "Modeling and Scheduling for An Intelligent Robot Assembly Cell." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/40855072549631920050.
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碩士<br>國立臺灣大學<br>資訊工程研究所<br>81<br>A timed place Petri net is used to model a robotic assembly
cell. We model our robotic assembly cell with three modules :
Robot-Task Handling Module, Assembly-Sequence Flow Module and
Material Control Module. The Petri net model can easily handle
the characteristics of assembly processing such as concurrency,
routing flexibility, and shared resources. The Robot-Task
Handling Module models assembly tasks with several control
signals. And we construct a Petri net model using the strategy
of controlling the number of unfinished subassembly to guide
our Robot-Task Handling Module, and the Petri net module is the
Material Control Module. On the other hand, an Assembly-
Sequence Flow Module can be constructed to reflect the routing
flexibility of assembly processing. In order to obtain an
optimal schedule and to avoid the NP-complete computing
complexity, we use a sub-optimal algorithm, based on the A*
heuristic search algorithm. We also use another approach for
modeling and scheduling of the robotic assembly cell. Firstly,
we model the assembly plan using AND/OR graph representation.
Secondly, a mathematical model of AND/OR graph is analyzed.
Finally, we use Neural Network approach to obtain a schedule.
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Ho, Chien-Yi, and 何阡邑. "Scheduling in Multi-Product Assembly Lines with Multiple Objectives." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/46359489839647302064.
Full textAbstract:
碩士<br>明志科技大學<br>工業工程與管理系碩士班<br>102<br>Flexible production scheduling in the assembly lines is useful for meeting the production due dates and reducing the production costs. This research considers the problem of scheduling multiple products on 2 or more assembly lines when multiple objectives exist. The specific objectives are to reduce the production changeovers and minimize overtime cost with the restrictions on production demands, due dates, setup time, and limited testing spaces. The system model derives from a real case of a company producing point of sale systems and a mixed integer programming model is established. Different sets of weights that represent the priorities of specific objectives are applied to the model. By manipulating and adjusting these weights, it is capable to provide the desired production schedule that satisfies production managers' need. An example has been solved for illustrating the method. The results show that the weighting approach is practicable and can provide valuable information for aggregate planning.
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Chou, ShieChieh, and 周世杰. "Batch Scheduling in a Three-Machine Assembly-Type Flowshop." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/77906722976133127486.
Full textAbstract:
碩士<br>銘傳大學<br>資訊管理研究所<br>89<br>This thesis addresses a three-machine assembly-type flowshop scheduling problem. Machines one and two are fabrication areas arranged as two parallel machines for producing component parts discretely, and machine three is an assembly line arranged as a flowshop for receiving component parts in batches. In this study, we explore useful properties for some special cases and present an NP-hardness proof for a special case. We define a lower bound for solutions to the generic three-machine assembly-type flowshop batch scheduling problem, and then devise several heuristic algorithms and dynamic programming procedures to find approximate solutions. Computational experiments are also conducted to study the effectiveness of the proposed algorithms. Finally, we give some concluding remarks and directions for possible further studies.
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林照棠. "A Study of Dynamic Scheduling in Machine Tools Assembly." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/22851474702955894785.
Full textAbstract:
碩士<br>逢甲大學<br>工業工程與系統管理學系<br>101<br>In Taiwan, the machine tools industry has become one of the most important industries over the last two decades. According to statistics, the Taiwan&;#39;s export sale of machine tools hit a record high of NT$100 billion in 2012. That led Taiwan to be the third largest machine tools producer in the world. This study focuses on dynamic production scheduling problem for a Taiwan machine tools manufacturer. The new orders for machine tools arrive continuously. The production schedule in shop floor must be updated every week. The objective of this study is to evaluate five dispatching rules for constructing each week’s dynamic production schedule under four different system conditions. The performance measures in this study are average number of completed machines per week, mean tardiness for each order, and the overall service level. The simulation model for this production system is developed using C++. The experimental data is collected for running the system for four years.
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Cheng, Hsing Hung. "Petri Net Modeling and GA Based Scheduling for Assembly Industry." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1207200410480500.
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Chen, Xing Jun, and 陳星君. "An automatic rulebase generator for scheduling of robotized assembly cell." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/18590794536423274471.
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Li, Hung-chieh, and 李宏傑. "A Two-Stage Assembly Scheduling Problem with Batch Setup Time." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/75756438600773628044.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>工業管理系<br>101<br>This thesis considers a two-stage assembly scheduling of products problem with setup time to minimize the makespan. In this problem, there is a machining machine in the first stage which produces components. When the required components are available, a single assembly machine in the second stage assembles these components into products. We formulate the problem as a mixed integer programming model and find several properties for the optimal solutions. Moreover, an efficient heuristic based on these optimal properties is proposed. A lower bound is also derived for evaluating the performance of the proposed heuristic. Computational results show that the heuristic can obtain a near optimal solution in almost zero time and the average percentage deviation is only 0.478.
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Cheng, Hsing Hung, and 鄭興宏. "Petri Net Modeling and GA Based Scheduling for Assembly Industry." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/97930361153600869777.
Full textAbstract:
碩士<br>國立臺灣大學<br>資訊工程學研究所<br>92<br>In this thesis, we propose a new dispatching rule and a new sequencing rule for assembly industry in order to obtain a better overall schedule. In addition, we use a graphical and mathematical modeling tool – Colored-Timed Petri Nets (CTPN) to model the scheduling flow in an assembly plant. By use of the proposed CTPN model, we can simulate the production under some scheduling policies. Moreover, we apply Genetic Algorithm (GA) to help the underlying scheduling mechanism to obtain a near-optimal solution.
In the scheduling phase, two effective rules have been proposed in addition to usage of a number of well-known methods. For the better ones, some use static information (such as setup time, processing time, due date, etc…), whereas others use dynamic information (such as remaining processing time, queue length, equipment workload, etc …). However, the aforementioned two proposed rules consider both static and dynamic information. Both set of rules together are proposed to construct the schedule. Generally speaking, these rules hold two viewpoints, namely, one is to select equipments for work order (WO) and another is to select (work order) WO for equipment.
Given such mechanism, we further apply genetic algorithm (GA) based approach to search for the optimal combination of the set of rules. Our approach can be considered as taking the advantage of obtaining the next fittest WO selection when the current WO finishes its assembly operation. The hereby proposed approach not only can increase the solution space but also can help us to locate a satisfactory solution. Besides that, the CTPN based GA scheduler takes less computation time than a lot of other schedulers, so that the present scheduler can meet the need for a rapidly changing environment.
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Chen, Yung-Yu, and 陳永育. "Multi-agent Based Dynamic Scheduling for a Flexible Assembly System." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/15859095864533889393.
Full textAbstract:
碩士<br>國立臺灣大學<br>資訊工程學系研究所<br>85<br>This thesis proposes a multi-agent based dynamic scheduling approach
for a flexible assembly system.
We first introduce a flexible control system developed by Intelligent
Robot and Automation Laboratory in National Taiwan University. Based on
that control system, the agents can communicate with each other conveniently.
A generic agent architecture is proposed to model the pieces of equipment
in the flexible assembly system. With a distributed architecture, the agents
make their scheduling decisions using their local rule base.
The agents acquire the resources following the distributed resource
allocation protocol.
The scheduling complexity is reduced to meet the real-time response
requirement in the applications for flexible automated production.
The present work is applied to the experimental robotized flexible assembly
system in the above laboratory.
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ZHANG, SHU-XUAN, and 張菽萱. "Design of scheduling system for flow-type flexible assembly systems." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/94988437633222945516.
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Hsin-JungYen and 嚴信榮. "Investigation and Implementation of Shipping Scheduling for Semiconductor Assembly House." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/58706399684490885207.
Full textAbstract:
碩士<br>國立成功大學<br>工學院工程管理碩士在職專班<br>100<br>For many years, Taiwan’s semiconductor industry has become pioneering and leading in the world, in particular in assembly industry. In order to maintain its superior edge and keep leading in this externally competitive violent environment, in addition to promote the relevant existing technologies for the advancement, the factory management has clearly become another crucial issue in keeping the leadership in the world. A fine factory management will mean how fewer the resources to achieve the maximum efficiency in the company. Therefore, the flexibility and efficiency of working in nature will become the most important issue that we shall all make the best effort to work towards.
By investigating some existing scheduling theories and applications, the purpose of this study is to establish a product shipping scheduling system for the Shipping Side in a semiconductor assembly house, aiming to achieve the production needs when the shipping scheduling has faced problems in shipping their production.
The shipment scheduling model is developed in this thesis based on such requirements as sorting rules, equipment restrictions, capacity planning and in particular considering four facets of the human scheduling in the company. Therefore, it is found that the proposed shipping scheduling system in this study is tailored with the company needs and hence it is very much efficient in equipment scheduling and flexible in staffing scheduling for employment in the company when their equipment stations facing the bottleneck problem in operation. Therefore, the revised shipping scheduling system is more systematic and adaptive in meeting any changes in the working patterns in the future. In addition, the established shipment scheduling model is also able to shorten the reaction time of the production need and to narrow down the marketing gap so as to strive for the flexibility of the Plant Side and then for undertaking a competitive environment to face the next challenge.
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Naphade, Kedar S. "A graph-theoretic framework for integrated assembly planning /." Diss., 1997. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:9730307.
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HUANG, SHI-SHUN, and 黃史舜. "The study of scheduling problem for an assembly type job shop." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/48163013920010526443.
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