ABSTRACT
This chapter describes a variety of job-shop scheduling models based on expanding both approaches to the case of jobs with different priorities and random time operations. For the case of a job-shop package without priorities a simplified solution is suggested. Various cost parameters have been introduced in the developed models. Most of the scheduling systems with jobs of different importance use heuristic procedures in combination with material requirements planning, capacity requirements planning, and master scheduling. In many manufacturing systems, job-operations are of random time duration even when being processed with a fixed average speed. A flexible manufacturing cell consists of a chain of operations each of which needs to be processed during an uninterrupted period on a given machine. In order to evaluate the performance of each heuristic a job-shop flexible manufacturing cell has been chosen. The developed unified decision model can be widely used in various job-shop Flexible manufacturing systems as a support tool.
