Abstract
From the general trend towards global markers and a growing customer orientation, new concepts and forms of organisation are emerging, such as distributed or networked enterprises. One key requirement of these new paradigms is the availability of models and tools to support order negotiation with the optimisation of manufacturing routes and logistics and ensuring the co-ordination of all participating entities. We address the problem of planning an incoming customer order to be produced in a distributed (multi-site) and multi-stage production system, in particular, we have used as a case study the industry of semiconductors (in the business area of application specific integrated circuits). The problem is tackled in a hierarchical model, in two levels: there is a global network planning procedure, and a set of local capacity models associated to the different production units reflecting their particular features. An approach based on simulated annealing is presented, as well as a specially designed constructive heuristic, that takes into account many of the real world constraints and complexities. The general performance of the simulated annealing algorithm is assessed through some preliminary computational experiments. Finally, some concluding remarks and current directions of research are presented.

Abstract
This paper describes a preliminary experience in trying to improve the communication and to reach language agreements in the context of a large R&D trans-national project, comprising partners with different academic and industrial cultures. This kind of projects has difficulties in that, besides cultural and language problems, the project teams undertake work largely by themselves, with reduced interaction with each other. The use of ontologies has a great potential in reducing those problems. Within this research work our goal is to extend the communication role of an ontology towards the mediation of the development actors ''world views''. In doing so, we intend to improve the engineering of an intrinsically complex software system, particularly in the requirements identification, system specification and system design phases, overcoming some of the referred difficulties. It is presented an extract of the Virtual Enterprise ontology currently under construction, focusing in some core definitions relevant for the purpose of developing a distributed planning and control software system. An example concerning the development of such a system is described in older to demonstrate the usefulness of the ontology based systems development.

Abstract
This paper presents a conceptual framework where the development of an information system for aggregate management of virtual / networked enterprises is taking place. Firstly, the general objectives of the system are described. An ontology based development approach is presented, assuming the role of conceptual guidance, both for the requirements analysis and design phases. Finally, a broad specification of aggregate management in this context is described through use cases.

Abstract
Traditional Production Planning and Control systems do not successfully deal with new organisational forms of manufacturing, like production "islands", product oriented or customer driven production. These current trends lead in practice to a strong decentralisation of production management tasks and to an "object oriented structuring" of the manufacturing process. Planning and operation in this global environment requires new skills and new approaches, namely, the co-ordination of global networks of manufacturing units and of large complex supply chains. In this paper, we present a decentralised information system designed to address the tasks of production planning that result from sales orders, originated in customers located anywhere in the world, and accomplished through a distributed manufacturing network. The system addresses the requirements of a make-to-order environment and is hopefully able to produce realistic satisfactory delivery dates. The information infrastructure designed and implemented using distributed object-oriented technology with a component based architecture has proven to be efficient and powerful, satisfying all the major tight requirements of information systems in an environment of distributed manufacturing.

Abstract
In this paper we present an information system architecture, addressing the needs of an advanced order planning system for industrial networked enterprises environments. Firstly, the general objectives of the system are described focusing on the relevant business processes identified. Then, the related general functionality (business solutions) of a distributed system supporting those processes is described, focusing on the particular case of order change acceptance. An agent based architecture supporting this business solution is outlined, emphasizing the agent framework and the legacy systems integration.

Abstract
Current Production Planning and Control Systems do not in general satisfy the needs and challenges of production networks, as they lack the capacity to appropriately support a co-ordinated and effective communication between heterogeneous manufacturing sites. This paper presents a new approach, based on the multi-agent systems paradigm, for a planning (order negotiation) system suitable for distributed and virtual enterprises. The infrastructure and planning methodology (based on negotiations) proposed in this paper, have been designed for planning orders, involving a large number of scattered manufacturing plants, used in different production stages, connected through a complex logistic subsystem. A Decision Support System has been designed around an architecture based on several intelligent agents communicating through the Knowledge Query Manipulation Language (KQML). Copyright (C) 1999 IFAC.