Production Plan Scheduling Rule

1, FCFS(first come, first served). Jobs are processed in the sequence in which they entered the shop.
2, SPT(shortest processing time). Jobs are sequenced in increasing order of their processing times. The job with the shortest processing time is first, the job with the next shortest processing time is second, and so on.
3, EDD(earliest due date). Jobs are sequenced in increasing order of their due dates. The job with the earliest due date is first, the job with the next earliest due date is second, and so on.
4, CR(critical ratio). Critical ratio scheduling requires forming the ratio of the processing time of the job, divided by the remaining time until the due date, and scheduling the job with the largest ratio next.