Workflow Planning in Holonic Manufacturing Systems with Extended Contract Net Protocol

Holonic manufacturing systems (HMS) provide a reconfigurable and flexible architecture based on the notion of holon to dynamically meet customers' requirements. Given an order with specific product demands and due date, a challenge is to design a problem solving platform to guide the holons in HMS such that the decisions made by the individual holons as a whole fulfill the order. The objective of this paper is to propose a problem solving platform that finds a set of minimal cost holons and the associated workflows to fulfill an order. To achieve these objectives, we combine multi-agent systems technology with Petri nets to design and implement HMS to fulfill the requirements of orders. We first propose architecture and a two-layer contract net protocol for planning order holons, product holons and resource holons in HMS. To determine whether it is feasible for a set product holons and resource holons to meet the order requirements, we propose Petri net models to capture the workflows and activities in product holons and resource holons, respectively. To realize the two-layer contract net protocol, we proposed a scheme for publication and discovery of holon services based on FIPA compliant multi-agent system platform. We develop a HMS system to solve the order planning problem.