An efficient mathematical model for a generalized production process

This study proposes an efficient mixed integer linear programming (MILP) model for a generalized job shop production process. In the process, a workstation contains one or multiple machines and each job visits some of the workstations in a specific sequence. It is allowed that a job visits the same workstation more than once. Although some similar processes were modeled by MILP in previous studies, the models are unable to solve problems that involve more than ten jobs due to high computational complexity. Our proposed model outperforms the best model that is identified among 23 research papers with regard to computational complexity. Simulation results show that our model is able to solve a problem with a dozen of jobs, which is classified as a large-scale problem in the literature.