Scheduling in flexible job-shop manufacturing system by improved tabu search

In modern manufacturing and production systems, flexibility has increased as a response mechanism toward changes. In such systems, a piece may have several flexible process programs. In this study, scheduling problem in flexible job-shop manufacturing production systems is studied with minimization objective function of make span (Cmax ) "and" average time in completion of pieces (C ) that is consistent with, just in time philosophy and management objectives of supply chain. Concerning problem being NP-hard, heuristic method is proposed to solve it based on tabu search algorithm which is compared with a hierarchical method. Performance criteria for comparison are "response quality" and "calculation time" in which results of numerical test approve the priority of tabu search algorithm in comparison to hierarchical method.