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Study And Realization Of Job-Shop Scheduling Rules Algorithm In Real Production System

Posted on:2005-01-28Degree:MasterType:Thesis
Country:ChinaCandidate:P D WuFull Text:PDF
GTID:2156360125454520Subject:Mechanical design and theory
Abstract/Summary:PDF Full Text Request
Job-Shop scheduling, a high simplification of practical production, is a coexistent problem in product manufacturing industry. Solving the problem well be the key to make the full use of resource, work out the rational production plan of workshop and enterprise, ensure the delivery just in time, increase the reputation of enterprise, gain the more consumers and get survival in the struggle. Job-Shop scheduling is a kind of combinatorial optimization problem very hard to solve. Many efforts have been made for several decades in order to solve the hard problem and made considerable achievement. But a large amount of work must be done if the problem is solved completely. Several problems in this field have been studied in depth and some good results have been obtained in this dissertation.1) The definiton of Job-Shop scheduling problem is given. Its characteristics are analysed. The possibility and complexity of it are discussed. And the main techniques and methods of solving it are reviewed.2) The concept of relativity between tasks, which is often concerned in project management, is taken into account in Job-Shop scheduling. In the past researches on Job-Shop scheduling, the relativity of finish-start is only conisderde in the same part's working procedures, which can't obviously reflect the reality of production system in machine facture enterprises accurately and intactly. The schedulings drawn form those researches are usually infeasible. There are possibly being four kinds of relativity in actual machine manufactural system, they are finish-start(FS), finish-finish(FF), start-start(SS) and start-finish(SF). Because the four relativities are introduced to actual job-shop schedulings in this research, thus various kinds of restraint of process technology in real production system are defined and reflected intactly and feasibility of Job-Shop scheduling are ensured.3) On the base of reviewing and analysing the relevant papers synthetically, according to the characteristics in real production system, the requistion on scheduling and considering the time complexity and space complexity of the algorithm, priority dispatcher rules is used to solve scheduling problem by regular algorithms. For priority dispatcher rules are strongly problem denpendent, that is, different rule has different perfomance for different problem and different input, eight kinds of different priority dispatcher ruleses are taken into account in this researchand the algorithms are given respectively.4) The corresponding application program is written in Java in this research. Ulteriorly, two classical benchmark issues on Job-Shop scheduling, namely FT06 and FT10, are carried on operation by utilizing the application program.5) Two anamorphosises of FT06 and FT10 are designed by cosidering relativity, and they are also carried on operation by utilizing the application program.6) The result of the four schedulings are analyzed in detail, the results validated the exactness and feasibility of the algorithm; the performances of the eight kinds of priority dispatcher rules, when used to different objectives, are analysed and evaluated further.
Keywords/Search Tags:Real Production System, Relativity, Job-Shop Scheduling, Priority Dispatcher Rules, Algorithm
PDF Full Text Request
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