OFF-LINE SCHEDULING A SIMPLE CHEMICAL BATCH PROCESS PRODUCTION PLAN USING THE ILOG SCHEDULER

This paper considers the application of event based constrained logic programming solutions for a typical multipurpose multistage batch proc ess scheduling problem using the ILOG scheduler software package, wher e resource requirements such as equipment items and feed materials etc . are considered in various combinations. The aim is to contrast the a pproach with established mathematical programming approaches. The solu tion is based on a heuristic approach where the process route of each product is considered separately along with their resource requirement s and each product is made in a campaign mode, where more than one bat ch of particular activity might be performed within a cycle, so that t he material balance within the system can be maintained. These solutio ns can be generated within very modest computation time but require co nsiderable preprocessing of the input data. This work has shown that t he ILOG system is fairly flexible and readily interfaced with external systems and can cope with the various constraints imposed on the prob lem. However, further work is required for testing large scale industr ial problems. (C) 1998 Published by Elsevier Science Ltd. All rights r eserved.