Modeling Multistage Production Systems by Timed Petri Nets

Abstract

In multistage production systems, products are manufactured from a combination of fabrication and assembly operations. The component materials, parts, subassemblies and so on required for the manufacturing of a given end-product is issued from the Bill of Materials (BOM), as currently defined in a Manufacturing Resource Planning (MRP) environment. Each type encompasses different activities that can be carried out concurrently and that requires a certain lead-time to accomplish. Some activities are also in conflict since the same component parts (or materials) can be used for different production operations (in different assemblies for instance). Due to the different levels of interactions and the activities lead-time, the overall production process behaves in real time as an asynchronous concurrent system. This makes it quite complicated to evaluate the system performances. This is the issue discussed in the paper, using a modeling based on timed Petri Nets.