KBSS: a knowledge-based job-shop scheduling systema

Abstract Abstract. A knowledge based job-shop scheduling system lKBSSr, which employs artificial intelligence techniques to solve general job-shop problems, is presented. The system consists of two main components: a knowledge base lKBSS modelr and a control mechanism. The KBSS model has a three-level architecture which captures, in frames, knowledge about the job-shop domain and the characteristics of individual job-shop problems. The control mechanism consists of two modules: the primary scheduler lPSr and the heuristic scheduler lHSr. PS is a rule-based scheduler built around a time-transcending heuristic which attempts to minimize the makespan and meet the due dates. If PS fails to meet the due dates then HS applies a combination of Aa and beam search techniques in the space of alternative solutions and returns the best alternative it finds. The emphasis on due dates is a distinctive feature of KBSS. Experience with evaluating the presented scheduling system...