A heuristic approach based on time-indexed modelling for scheduling and tool loading in flexible manufacturing systems

In this paper, we simultaneously consider the scheduling and tool loading problems in flexible manufacturing systems. There are various jobs that must be processed on a number of parallel computer numerical control machines. The processing of each job requires a set of machine tools. However, the number of tool copies available in the system is limited due to economic restrictions. The problem, therefore, is to schedule the jobs and the required tools in such a way that the makespan is minimized. We present a time-indexed mathematical model of the problem. A heuristic approach based on the mathematical model is also developed and the computational results are presented. The goal of this study is to develop a new approach for simultaneously scheduling the jobs and loading the tools in flexible manufacturing systems and benefit from the advantages of time-indexed modelling.