Intelligent Backtracking Techniques for Job Shop Scheduling

This paper studies a version of the job shop scheduling problem in which some operations have to be scheduled within non-relaxable time windows i.e. earliest latest possible start time windows. This problem is a wellknown NP-complete Constraint Satisfaction Problem CSP. A popular method for solving these types of problems consists in using depth- rst backtrack search. Our earlier work focused on developing e cient consistency enforcing techniques and e cient variable value ordering heuristics to improve the e ciency of this procedure. In this paper, we combine these techniques with new lookback schemes that help the search procedure recover from so-called deadend search states i.e. partial solutions that cannot be completed without violating some constraints. More speci cally, we successively describe three intelligent backtracking schemes: Dynamic Consistency Enforcement dynamically enforces higher levels of consistency in selected critical subproblems, Learning From Failure dynamica...

• Type: Conference
• Year: 1992
• Where: KR
• Authors: Yalin Xiong, Norman M. Sadeh, Katia P. Sycara
• Keywords: Automated Reasoning, Job Shop Scheduling, KR 1992, Search Procedure, Shop Scheduling Problems