Scheduling Preemptive Open-shop to Minimize Total Completion Time

• Main Authors: Chih-Yi Wang, 王智毅
• Other Authors: Ching-Fang Liaw
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/8sp4v2

碩士 === 朝陽科技大學 === 工業工程與管理系碩士班 === 94 === Production scheduling is very important in practice . A good scheduling can order the jobs efficiently , improve the machine utilization and reduce the production cost . Currently , the research of production scheduling is getting more and more emphasized . In this research the scheduling problem of minimizing total completion time in a preemptive open shop is examined . The open shop preemptive scheduling problem can be formulated as follows . There are n jobs that have to be processed on m machines . Each job consists of m operations each of which is to be processed on a different machine. The order in which the operations are processed is immaterial . Each job is processed by one machine at a time and each machine processes one job at a time . A schedule is preemptive if the execution of any operation may arbitrarily often be interrupted and resumed at a later time . Given a job completion sequence , the problem can be expressed as a linear program . When the number of machine is two , the linear program can be replaced by an algorithm with complexity O(n) which produces no more than n-1 preemptions . When the number of machine is greater than two , we develop an efficient heuristic for solving the total completion time preemptive open shop scheduling problem. Finally , computational experiments are conducted to evaluate the performance of the proposed algorithm . The Heuristics presented in this research can solve m-machine problem efficiently. Also, HeuristicⅡperforms better than HeuristicⅠ. Keyword：Scheduling , Open shop , Preemptive , Total Completion Time