A GASP simulation study of job-shop scheduling

Abstract

The purpose of this paper is to report on a study which involves a simulation of a hypothetical job shop with several machines. The investigation employs GASP-II as a computer language. This simulation study is concerned with: (1) testing a new method of assign ing job due-dates and (2) comparing and evaluating the effect of different processing-time distributions on the performance of a number of scheduling rules. The most significant results of this study are: (1) The shortest-imminent-operation rule is superior to others in reducing job lateness and shop flow time (2) The procedure in which the due-date allowance is proportional to the number of operations and work content of the jobs has proved to be beneficial in the case of the non-due-date rules (3) The operation of a job shop using the shortest-imminent-operation and slack-per-remaining-number-of-operations rules is degraded when the processing-time distribution having Erlang parameter K equal to 4 or 8. However, per formance is better when K = 8 than when K = 4 (4) The GASP-II package works efficiently for large-size shop problems.