Simulation optimization for a flexible jobshop scheduling problem using an estimation of distribution algorithm

The flexible jobshop scheduling problem permits the operation of each job to be processed by more than one machine. The idea is to assign the processing sequence of operations on the machines and the assignment of operations on machines such that the system objectives can be optimized. The assignment mentioned is a difficult task to implement on real manufacturing environments because there are many assumptions to satisfy, especially when the amount of work is not constant or sufficient to keep the manufacturing process busy for a long time, causing intermittent idle times. An estimation of distribution algorithm-based approach coupled with a simulation model is developed to solve the problem and implement the solution. Using the proposed approach, the shop performance can be noticeably improved when different machines are assigned to different schedules.