Fault-tolerant holonic manufacturing systems

This paper presents a model of fault-tolerant holonic manufacturing systems (HMS) where each holon's activities are controlled by an intelligent softw are agent. Multiple agents schedule actions, resolve conflicts and manage i nformation to produce, transport, assemble, inspect and store customized pr oducts. Our model provides robustness and distribution transparency across a shop-door where unpredictable failures occur with machines, control softw are and communication networks. Each autonomous holon is composed of a hier archy of large-grain functional components where interaction is carried out by user-defined cooperation strategies. These strategies enable holons to coordinate their behaviour through exchanging messages and sensing/actuatin g of their shared environment. Therefore, holonic agents can select suitabl e rescheduling and recovery mechanisms to tolerate faults and keep the manu facturing system working. We also propose how the IEC 1499 standard (Functi on Block Architecture) for distributed control systems could be used to imp lement our model. The model presented here is a crystallization of some abs tract concepts from a generic cooperating agent system, with suitable exten sions to meet the criteria of the ongoing HMS project. Copyright (C) 2001 J ohn Wiley & Sons, Ltd.