Minimizing job flow time for job oriented scheduling

This paper presents a multi-pass scheduling procedure for minimizing flow time of individual jobs scheduled by job oriented scheduling in a job shop environment. Forward finite loading and backward finite loading are applied between the operations of a job or between a set of assembled jobs to enable them to be scheduled as close to one another as possible, thus minimizing job flow time. Examples are given to illustrate the scheduling procedure for minimizing flow time of a job by forward or backward scheduling. Experiments conducted for examining the effectiveness of the procedure show that it significantly reduces the average flow time of the jobs for the problems tested. The more diversified are the jobs scheduled in terms of their routing sequence and operation attributes, the more effective the procedure.