Applying Fuzzy Logic to Estimate Setup Times in Sequence Dependent Single Machine Scheduling Problems

Single machine scheduling problems with earliness and tardiness penalty are well known, but in the case of sequence dependent, the problem is more difficult and there are few researches around it. In related researches, setup time matrix was defined as a deterministic matrix. In this paper sequence dependent single machine scheduling with earliness tardiness penalty considerations using fuzzy setup time is presented. It is assumed that setup times are dependent on both of, level of technology (for machine) and degree of operation's similarity (between two precedence operations in the sequence). When setup time matrix (base on real situations) obtained, the problem can be solved using common methods available in the literature. Twoway analysis of variance clearly indicated the superiority of the proposed approach in comparison of simulated results