Mixed Integer Programming for Integrated Flexible Job-Shop and Operator Scheduling in Flexible Manufacturing Systems.

In this paper, we propose a mixed-integer programming model for an integrated flexible job shop and operators shift-based scheduling in a Flexible Manufacturing System (FMS). The objective is to schedule a given set of jobs while taking operators schedule into account. Operators are qualified to operate a set of machines, and thus are only able to execute operations scheduled on these machines during their active shifts. An operation can be executed on a qualified machine in presence of a qualified operator. Furthermore, we tested the proposed MIP model on a set of generated instances to evaluate its performances. The MIP model provides optimal solutions for small scale instances. For larger instance the computational time and solutions gaps are still quite high. We are currently investigating how to reduce the computation time and improve the gaps for industrial size problems.