Combining LR and 2-opt for scheduling a single machine subject to job ready times and sequence dependent setup times

摘要

In this research, the job ready times and sequence-dependent setup times of a single machine scheduling problem are considered with the objective of makespan minimization. As the problem is NP-hard, a Lagrangean Relaxation (LR) approach is proposed to find an initial solution and a heuristic based on 2-opt was implemented to improve it. Extensive computational experiments showed that the proposed combination of LR and 2-opt is effective. Wide range of test problems from 25 to 75 jobs was studied. The performance of the proposed approach was compared with the results from a commercial solver.