Abstract
Partner selection in virtual enterprises (VE) can be viewed as a multi-criteria decision making problem that involves assessing trade-offs between conflicting tangible and intangible criteria. In general, this is a very complex problem due to the dynamic topology of the network, the large number of alternatives and the different types of criteria. In this paper we propose an iterative and interactive exploratory process to help the decision maker identify the companies that best suit the needs of each particular project. This is achieved by using cluster analysis to distinguish companies according to some selected features. We present an example to illustrate this approach.

Abstract
We consider the formulation of non-preemptive single machine scheduling problems using time-indexed variables. This approach leads to very large models, but gives better lower bounds than other mixed integer programming formulations. We derive a variety of valid inequalities, and show the role of constraint aggregation and the knapsack problem with generalised upper bound constraints as a way of generating such inequalities. A cutting plane/branch-and-bound algorithm based on these inequalities has been implemented. Computational experience on small problems with 20/30 jobs and various constraints and objective functions is presented.

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.

Abstract
This paper describes an attempt to design an "Order Promise" system to support decision making in the so-called Virtual Enterprises. In this framework, planning and control activities are very complex, and have to take place both within the enterprise and across the whole supply network in order to achieve high levels of performance. This work is part of a broader project with a particular focus on the microelectronics industry which is a good example of Virtual Enterprise, and where a quick response to the customers needs and to unpredictable changes in production conditions is considered a major factor for success. Copyright (C) 1998 IFAC.

Abstract
This paper describes an <> system to support decision making in the planning processes of Virtual Enterprises, viewed as networks of different units, namely plants, logistic centres and storage facilities. The system aims at improving customer due date calculation, and is intended to be a multi-site planning tool to co-ordinate local activities across the Virtual Enterprise network. It is based on the use of aggregate information and on a set of local rough capacity models. This work is part of a broader project with a particular focus on the microelectronics industry. Companies of this industry are a good example of Virtual Enterprises, where a quick response to the customers needs and to unpredictable changes in production conditions is considered a major factor for success.