Reference architecture for holonic manufacturing systems: PROSA

Future manufacturing systems need to cope with frequent changes and disturb ances. As such, their control requires constant adaptation and high flexibi lity. Holonic manufacturing is a highly distributed control paradigm that p romises to handle these problems successfully. It is based on the concept o f autonomous co-operating agents, called 'holons'. This paper gives an over view of the holonic reference architecture for manufacturing systems as dev eloped at PMA-KULeuven. This architecture, called PROSA, consists of three types of basic holons: order holons, product holons, and resource holons. T hey are structured using the object-oriented concepts of aggregation and sp ecialisation. Staff holons can be added to assist the basic holons with exp ert knowledge. The resulting architecture has a high degree of self-similar ity, which reduces the complexity to integrate new components and enables e asy reconfiguration of the system. PROSA shows to cover aspects of both hie rarchical as well as heterarchical control approaches. As such, it can be r egarded as a generalisation of the two former approaches. More importantly, PROSA introduces significant innovations: the system structure is decouple d from the control algorithm, logistical aspects can be decoupled from tech nical ones, and PROSA opens opportunities to achieve more advanced hybrid c ontrol algorithms. (C) 1998 Elsevier Science B.V. All rights reserved.