Abstract
This paper presents some lines of thinking related with the establishment of a concrete mathematical basis to measure the ability of enterprises in a supply chain to maintain equilibrium under unexpected variations. It will be argued that flexibility will be the most appropriate term to classify the concept behind such idea and that agility can be understood as a special case of flexibility. Then, a simple theory of flexibility directed to demand variations in the supply chain is deduced and commented, as well as some results achieved by dynamic supply chain simulation presented and discussed.

Abstract
Here we present a computer application planned to be used as an interactive tool for Supply Chain Management Training. Implemented with Visual C++, this application embeds the "Cranfield Blocks Game" (Richard Saw, 2002) network structure, and uses precisely the same demand patterns as the manual version of the game. Anyhow, instead of reducing the play to 12 reorder cycles, as the manual version does, this application extends those patterns throughout the time till any number of reorder cycles, what let the results become more useful and interesting even for didactic purposes. At the same time, the present application substitutes the classroom table by the computer screen, and can be made to run in AUTOPLAY mode, meaning the game can also be played with only one player or even automatically, with no players at all. In a certain way, this comes closer to some kind of Distributed Supply Chain Simulation, apart from the fact each lead time is fixed, as the "Cranfield Blocks Game" states, and the AUTOPLAY stock policy is empirical. As each application communicates with the SERVER using the TCP/IP protocol, the players can be spread by different computers and even placed at different geographic locations if connected to the INTERNET. In the end of this paper, results achieved with an automatic running session and with the involvement of a group of students from the Escola de Gestao do Porto (EGP) will be presented and compared.

Abstract
In this paper an application of constraint logic programming (CLP) to the resolution of nesting problems is presented. Nesting problems are a special case of the cutting and packing problems, in which the pieces generally have non-convex shapes. Because of their combinatorial optimization nature, nesting problems have traditionally been tackled by heuristics and in the recent past by meta-heuristics. When trying to formulate nesting problems as linear programming models, to achieve global optimal solutions, the difficulty of dealing with the disjunction of constraints arises. On the contrary, CLP deals easily with this type of relationships among constraints. A CLP implementation for the nesting problem is described for convex and non-convex shapes. The concept of nofit polygon is used to deal with the geometric constraints inherent to all cutting and packing problems. Computational results are presented. © 2003 Wiley Periodicals, Inc.

Abstract
In this paper, the Unit Commitment (UC) problem is presented and solved, following an innovative approach based on a metaheuristic procedure. The problem consists on deciding which electric generators must be committed, over a given planning horizon, and on defining the production levels that are required for each generator, so that load and spinning reserve requirements are verified, at minimum production costs. Due to its complexity, exact methods proved to be inefficient when real size problems were considered. Therefore, heuristic methods have for long been developed and, in recent years, metaheuristics have also been applied with some success to the problem. Methods like Simulated Annealing, Tabu Search and Evolutionary Programming can be found in several papers, presenting results that are sufficiently interesting to justify further research in the area. In this paper, a resolution framework based on GRASP - Greedy Randomized Adaptive Search Procedure - is presented. To obtain a general optimisation tool, capable of solving different problem variants and of including several objectives, the operations involved in the optimisation process do not consider any particular characteristics of the classical UC problem. Even so, when applied to instances with very particular structures, the computational results show the potential of this approach.

Abstract
This article presents the results of a qualitative study of a Portuguese bank regarding customer use of Internet banking integrated in a multi-channel offering that includes high street branches, telephone banking, and automatic teller machines. The results show that performance evaluation is a key factor influencing channel use. Customers tend to use the different service delivery systems in a complementary way, taking into account their assessment of the advantages and disadvantages of each one. Customer characteristics, and the type of financial operation, are also identified as important factors influencing this process. These results indicate that, in a multi-channel context, customer satisfaction with Internet services depends not only on the performance of this channel in isolation, but also on how it contributes to satisfaction with the overall service offering. © 2003, MCB UP Limited

Abstract
This article presents the results of a qualitative study of a multi-channel bank. It aims at developing new methods of gathering user requirements for web interfaces, joining HCI and Marketing perspectives. The results obtained so far indicate that, as most of financial operations are functionally available in the different service channels, experience requirements become increasingly important. In this context, essential use cases are particularly valuable in improving the process of gathering customer requirements. As they allow the analysis of users' interaction needs in a channel-independent way, their use can improve decisions on what services are best suited to each channel, to effectively address customer needs across different interaction modes, and make an efficient allocation of resources among channels.