Chemical Reaction Optimization for Earliness-Tardiness Scheduling Problem

This paper studies a job shop scheduling problem on a single machine environment with an objective of minimizing the total weighed earliness and tardiness penalties. Jobs have distinct release dates and distinct due dates. A sequence-dependent setup times exists between two consecutive jobs. Jobs are punished if they are finished either before due dates or after due dates. A chemical reaction optimization method is proposed to solve the problem. An improved optimal timing is applied to fix the start time of each job under given sequence. Experimental results show that the proposed algorithm can solve this problem effectively.