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Optimization of a single-item repairable inventory system with new and warranty demand.January 2014 (has links)
退貨産品在國民經濟中發揮重要作用,近些年來在工業界和學術界引起廣泛關注。由于受到退貨産品的巨大經濟潛能驅動以及迫于相關法律的強大壓力,企業開始積極整合現有供應鏈流程和産品退貨流程,但是在這個過程中生産計劃和庫存管理運營遇到了前所未有的挑戰。本論文分析了可修護單壹産品的多周期庫存系統管理問題,其中該庫存系統包含隨機的新産品需求和産品保修需求。所探討的系統還包含了以下特征: i. 産品供應源的完美替換。新訂購産品和維修後的退貨産品並無二異。ii. 需求優先級。在單個周期內,新産品需求優先級高于保修需求。iii. 新産品訂購和退貨産品維修特性。兩項流程交付時間都假設爲零。在每個周期中,維修退貨産品過程涉及且考慮維修損失。我們探尋到了所考察系統的最優庫存補貨和處理控制策略。 / Product returns play an important role in the economy and have attracted more and more attention both from industry and academia in the past few years. Motivated by enormous economic potential of and dramatic legislation pressure on product returns, companies today actively integrate product-return processes with their existing forward supply-chain processes, but must confront the considerable challenge of production planning and inventory control problems compared to traditional problems without returns and repairs. / This thesis analyzes a multi-period single-item repairable inventory system with stochastic new and warranty demands. The system investigated has the following features: i. perfect substitution of supply sources. Newly-procured items are indistinguishable from items repaired from repairable warranty returns. ii. demand priority. New demand has higher priority than warranty demand within a period and thus needs to be satisfied first. iii. properties on the processes of purchasing and repairing. We assume zero lead-time for both processes. Further we capture the "repair loss" in repairing returns in each period. We identify the optimal inventory replenishment and disposal policies for the investigated system. / Detailed summary in vernacular field only. / Lin, Yizhong. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 80-87). / Abstracts also in Chinese.
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Batch scheduling in supply chainsSelvarajah, Esaignani. Steiner, George, Unknown Date (has links)
Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: George Steiner. Includes bibliographical references (leaves 123-126). Mode of access: World Wide Web.
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Planning and implementing a manufacturing control system in a job shop environmentMaplestone, Robert N. 08 January 1999 (has links)
This thesis is intended to provide the management of small to medium sized job shop
companies with a written plan to implement a formal computerized manufacturing
planning and control system. The research stemmed from a case study performed at a
typical job shop where growth of production activities was complicating the informal
control system being used. A review of the literature and a survey of job shops provided
the necessary foundation for this implementation. Research indicated that typical material
requirements planning (MRP) systems do not provide the type of shop floor control that
most job shops require. This thesis suggests alternatives that not only provide the type of
shop floor control required by a typical job shop, but software that can be managed
effectively by current employees with minimal changes to the education and training of
these employees.
The plan contains ten steps that are designed to be used by a job shop wishing to
implement a formal computerized control system. A decision making heuristic is used in
the first step that provides a method for estimating the benefits that might result from
implementation. Sample criteria for evaluating current shop floor control software,
development of an implementation timeline, cost considerations, educational
requirements for employees, and suggested methods for measuring project performance
are also included. Examples of the type of improvement that can be expected for each of
the business activities is also discussed.
The overall goal is to provide a comprehensive plan that will guide managers through
the steps necessary to implement a computerized shop floor control system and to inform
managers of the benefits which can accrue from such a system. / Graduation date: 1999
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Component to multi-track feeder assignment and board sequencing for printed circuit board assemblyLi, Yu-An 19 March 1999 (has links)
This research was motivated by the use of multi-track feeders in the printed
circuit board (PCB) assembly. In a low volume, high mix production environment,
setup time is usually considered more important than processing time. Implementation
of multi-track feeders not only increases the capacity of the surface mount
machines but also reduces feeder changeovers. However, improper planning could
diminish these benefits.
The objective of this research is to develop a process plan to minimize the
feeder setups in multi-track feeder systems. Two problems have been identified:
component to multi-track feeder assignment problem and PCB sequencing problem.
The assignment problem is formulated as a multi-dimension symmetric assignment
problem with an integer-programming model. The objective is to maximize the total
similarity of the component assignment. This optimization model is implemented
for small-sized problems using a commercial solver package. Due to NP-complete
characteristics, heuristic algorithms are developed for solving large-scale problems
and industrial cases. The Hungarian algorithm, designed for asymmetric assignment
problems, is used to reduce problem size in the double feeder case.
The PCB sequencing problem is solved in three stages: component and PCB
grouping, intra- and inter-group PCB sequencing, and feeder setup planning. An
optimal tool switch policy called Keep Tool Needed Soonest is adapted for planning the multi-track feeder setup. This research also identifies the interrelationship of the assignment problem and PCB sequencing problem. An optimal component to feeder assignment will show real advantages only when working with a well-planned PCB sequence.
Data obtained from literature are used to verify the heuristic developments. The methods are also applied to industrial data for evaluation of performance of real-world problems. Experimentation is conducted with simulation data to investigate the performance of methodology for different production situations. The results show that savings of up to 85% in feeder setups can be realized with a double feeder system compared to a single feeder system, with the use of the developed methodology. The approach is also robust and efficient for different production environments. / Graduation date: 1999
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An investigation of an alternative to acceptance sampling through a Markov chain analysis of a manufacturing process quality control programHarrington, Daniel F. January 1990 (has links) (PDF)
Thesis (M.S. in Operations Research)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Lindsay, Glenn F. Second Reader: Bailey, Michael P. "September 1990." Description based on title screen as viewed on December 21, 2009. DTIC Identifier(s): Quality control, sampling, acceptance tests, production control, theses, mathematical models, vendors. Author(s) subject terms: Markov chain, P-chart, fraction nonconforming vs AQL. Includes bibliographical references (p. 50). Also available in print.
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Operation based facilities design /Chittratanawat, Sarawoot, January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 396-419). Also available on the Internet.
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Constraint-based supply chain inventory deployment strategiesStremler, David Jay. January 2001 (has links)
Thesis (M.S.)--Mississippi State University. Department of Industrial Engineering. / Title from title screen. Includes bibliographical references.
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Operation based facilities designChittratanawat, Sarawoot, January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 396-419). Also available on the Internet.
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Facility layout using layout modulesHuang, Heng. January 2003 (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xii, 156 p. : ill., (some col.). Includes abstract and vita. Advisor: Shahrukh A. Irani, Dept. of Industrial and Systems Engineering. Includes bibliographical references (p. 147-156).
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Influence factors of engineering productivity and their impact on project performanceLiao, Pin-chao, 1977- 09 October 2012 (has links)
Effective management of engineering productivity is critical to achieving overall project success (CII 2001). Although engineering cost has approached to the level of 20 percent of a project’s total cost on some industrial projects, engineering productivity is not well understood. For these reasons, the Construction Industry Institute (CII) developed an Engineering Productivity Measurement System (EPMS) that consists of quantity-based metrics to directly measure engineering productivity, and drive continuous performance improvement. However, barriers to system implementation exist. Productivity metrics in the EPMS are measured for various disciplines and thus evaluating overall productivity was initially difficult because of the lack of a summary metric. Because the EPMS is still new to the industry, limited understanding of its metrics has presented a challenge to gaining acceptance for its use in benchmarking. This has inhibited the realization of its potential for supporting improvement. Now that a dataset for the EPMS has been compiled, however, analyses can be performed to support research and the resulting findings will help to overcome implementation barriers of the EPMS. The author developed this research with data from the EPMS and input from industry. Feedback was collected in CII training sessions, committee meetings, and industry forums. The researcher undertook quantitative analyses using the EPMS data. The results will assist industry practitioners to effectively monitor and manage engineering process to reach project success. Four main objectives were achieved in this study: 1) discipline and project level indices to summarize engineering productivity were constructed; 2) influence factors as a foundation of engineering productivity improvement were identified; 3) discipline information dependencies were measured quantitatively; and 4) the associations between engineering productivity and project performance were documented. / text
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