APPLYING AN ADAPTIVE PETRI NET TO CALCULATE THE MAKESPAN IN THE JOB SHOP SCHEDULING PROBLEM

Abstract

The Job Shop Scheduling Problem (JSSP) is one of the typical problems that engineers face on designing Flexible Manufacturing Systems (FMS). In this problem, it is important to find the optimal scheduling to perform a set of tasks in the minimum time. Moreover, the JSSP has some restrictions, such as the tasks order and the number of shared resources where the tasks are carried out. To find the optimal tasks sequence it is necessary to obtain the makespan for each sequence. On this way, FMS can be modeled with Petri nets (PNs), which are a powerful tool that have been used to model and analyze discrete event systems. So, the JSSP can be analyzed in a PN representation of the FMS, and the makespan can be calculated by using the PN model. In this work we propose an adaptive PN to obtain the makespan by applying PN analytical tools.