An optimization approach for scheduling of jobs on lines of press machines

Abstract

In this study, the aim is to maximize the capacity utilization of a press line using mathematical tools in given or optimized time frames. Similar to a facility layout problem, the jobs to be scheduled are optimally located and fitted into a rectangular frame where the horizontal length is the lime horizon of the scheduling effort and the vertical length is the total number of press machines ordered sequentially line after line. A mixed integer programming model is established in order to fill in the rectangular time-machine frame with small rectangular time-operation job elements without any overlap among elements. Depending on the number of job elements in a scheduling period, the problem earn conveniently be handled by known branch and bound algorithms and such a sample problem is solved here for demonstrative purposes. Application of this scheduling optimization is currently being tested in a car manufacturer's press shop to be integrated into an existing manufacturing resource planning system.