A holonic approach for task scheduling in manufacturing systems

This paper deals with a new architecture and negotiation protocol for the dynamic scheduling of manufacturing systems. The architecture is based on two paradigms: multi-agent systems and holonic systems. The main contribution in the architecture is the existence of holons representing tasks together with holons representing resources. The well known contract net protocol has been adapted to handle temporal constraints and to deal with conflicts. The purpose of this protocol is to dynamically assign operations to the resources of the manufacturing system in order to accomplish the proposed tasks. This protocol involves a renegotiation phase whenever exceptions appear. It also deals with conflict situations, namely with the case of the “indecision problem”. The approach we are using assumes that deadlines are the most important constraints to consider, thus the acceptance or refusal of a resource for a specific operation depends on the capability of executing the operation in the specified deadline