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Theory Of Constraints-Based Method And Application Of Production Scheduling In The Hybrid Flow Process

Posted on:2009-10-12Degree:MasterType:Thesis
Country:ChinaCandidate:H J WangFull Text:PDF
GTID:2189360242976583Subject:Industrial Engineering
Abstract/Summary:PDF Full Text Request
Hybrid Flow Shop (HFS) scheduling problem is a kind of complicated scheduling problems which involve task, resource and time. HFS belongs to NP-Hard Problem, which is difficult to build exact mathematical model. Currently it is mainly solved by some modern optimization algorithms such as heuristic, branch and bound, local search and so on. In this thesis the DBR control strategy in the Theory of Constraints (TOC) is applied to solve the Hybrid Flow Shop (HFS) scheduling problems with reentrance, batch processing and constraints on work in process (WIP). A layered scheduling module is established for the different objectives and methods of scheduling. In the upper layer an integer linear programming is adopted based on TOC, which simplified the dynamic scheduling problem into a static resource allocation one. An integer linear programming with order objective and capacity constrains on resource in the shop is used to solve the production plan. The phenomenon of stage bottleneck shifting in multi-order system and the efficiency of source allocation is well analyzed in this layer. The middle layer is buffer controlling of bottle. This layer protects the capacity of bottleneck based on Drum-Buffer-Rope (DBR) control strategy and inserts a job selecting rule on the job-release time to balance the Capacity Constraint Resource (CCR) which was cause bottleneck shifting under the constraints of Work in Process (WIP). In the layer emphasis is put on the analysis of the reason of bottleneck shifting and design of the buffer size. The bottom layer schedules the process of machine, which adopts simple heurist rules to reduce the scale of operation and improves the stability of system. The special machine such as reentrance is accordingly handled to hold the stable stream of jobs.
Keywords/Search Tags:Printed circuit board(PCB), Theory of constraints, Bottleneck, Branch and bound, Scheduling
PDF Full Text Request
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