Summary: | 碩士 === 朝陽科技大學 === 工業工程與管理系碩士班 === 94 === The flowshop scheduling problem can be stated as follows. There are n independent jobs and m different machines. There is restriction on the order in which the operations of a job are to be performed. Each machine can process at most one job at a time and each job can be processed on one machine at a time. flowshop scheduling are often encountered in mass production systems.
Scheduling problems with no-wait constraints occur in many industries. For instance, in hot metal rolling industries , where the heated metal has to undergo a series of operations at continuously high temperatures before it is cooled in order to prevent defects. Similarly , in the plastic molding and silverware production industries, a series of operations must be performed to immediately follow one another to prevent degradation.
We consider the problem of total completion time in a two-machine no-wait flow shop environment. In our research, we present a heuristic solution method for solving large-scaled problems. We also develop a branch and bound algorithm. We use an upper bound based on the heuristic algorithm developed, and propose some dominance rules to help pruning unpromising nodes in the branch-and-bound search tree. Finally, computational experiments are conducted to evaluate the performances of the proposed algorithms. The algorithms can efficiently solve problem with 30 jobs.
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