Collaborative timed Petri net for holonic process planning

Abstract

Holonic manufacturing system (HMS) is a paradigm based on cooperative multi-agent system theory to effectively configure resources to deal with uncertainties in today's manufacturing environment. Optimization of HMS is a challenging problem owing to the distributed multi-agent system architecture and sophisticated collaboration processes among agents. Direct application of contract net protocol is not feasible due to the lack of capabilities to model and compute the cost function of the complex production processes. This paper focuses on the development of a framework to optimize the performance of HMS by extending the contract net protocol with timed Petri nets. By combining the capability of collaboration and coordination offered by contract net protocol with the advantages of Petri net theory in modeling and analysis of complex production processes, we propose a class of collaborative Petri net (CTPN) to adaptively model the holonic manufacturing processes and to optimize the throughput or works in process. An algorithm is proposed to facilitate the computation of the cost function based on CTPN models.