MODELING, SCHEDULING AND SIMULATION OF FLEXIBLE MANUFACTURING SYSTEMSUSING EXTENDED STOCHASTIC HIGH-LEVEL EVALUATION PETRI NETS

The present paper presents the new extended stochastic high-lea el eva luation Petri nets (ESHLEP-N) which are more suitable for modelling an d simulation of flexible manufacturing systems (FMSs). The advantages of ESHLEP-N lie in the fact that their resulting models are not only s impler, more intuitive and more descriptive, but also of the more infe rential and decisive power. Based on the ESHLEP-N model, the schedulin g and simulation expert system (ES) for the FMS is designed and establ ished. With the help of the ES, we will put forward some new dynamic-r escheduling rules aiming at reducing no-inputs and blockings, The simu lations show that the throughputs of the rescheduling can increase on an average by 6.48% as compared with those of the non-rescheduling. Th e comparison between the experiment on the real FMS and the simulation on the ES indicates that the ES is effective. (C) 1998 Elsevier Scien ce Ltd. All rights reserved.