工件不允許等待之平行機台流程式生產排程

Abstract

本論文探討NWF-P排程問題及機台績效，該問題的情境如下：多階段不允許等待加工限制的流程式生產，第一階段具平行等效機台，其餘階段皆為單一機台的生產系統。本論文根據上述問題特性，以總排程時間最小化為目摽，以三階段的排程情境為例，提出兩套以禁忌搜尋法為架構的演算法(TS_T、TS_P)求解NWF-P排程問題，並將演算結果與既有的NWF、平行機排程等方法比較，結果發現TS_P的排程結果顯著優於其他演算法，亦證明平行機台影響整個排程結果甚鉅。最後，為衡量平行機台績效，根據排程結果並利用統計方法計算機台利用率、工件逾期比例等資訊，提供決策者決定系統中設置的平行機台數目。

This study addresses a no-wait flowshop scheduling problem with parallel machines at the starting stage. We proposed two effective methods, called TS_T and TS_P, to determine the jobs sequence, which is a priority list of the processing order for the jobs in the final schedule. Several examples are designed to show that the proposed heuristics are accurate and outperform the existing methods used to solve a no-wait flowshop problem and a parallel machines scheduling problem. Furthermore, based on the scheduling results produced by the proposed heuristics, the marginal benefits of parallel machines have been analyzed and are believed to support decision-making of the number of the appropriate number of parallel machines in starting stage.