Abstract
One of the issues in the shoe industry is that market seeks the fulfilment of product orders for smaller production lots with shorter deadlines. A need therefore arises to respond to these market changes. Such a response includes amongst other things improving the internal organization of the enterprise, by for example rationalizing the production floor layout. A portuguese shoe factory decided to cut costs related to the transportation of all work in progress within the factory plant by implementing a fully automated storage and retrieval system. This Paper presents the development of a Simulation model, using the Arena simulation software tool, to analyse the performance of the automated storage and retrieval system based oil a number of scenarios. The simulation model uses VBA (Visual Basic for Applications) to implement the control logic and graphics to Visualize the sequences of movements and storage / retrieval operations.

Abstract
Purpose - The purpose of this paper is to determine the state probabilities for a float system when overhauls are performed periodically. Design/methodology/approach - First, a model is developed to express the relationship between the rate of occurrence of failure and time interval between overhauls. Then, a methodology is defined to develop differential equations for each system state in order to calculate corresponding system state probabilities. Findings - Since it is considered that units requiring an overhaul stay in operation until replacement, the possibility of failure of those units has to be included. Then, the determination of system state probabilities has to be done iteratively. Practical implications - The methodology proposed in this paper enables comparison of different designs for a float system submitted to periodic overhauls through some different performance measures. System state probabilities can also be used to determine the idle time of units, which is essential to obtain the cost of production loss and, therefore, the system maintenance cost. Originality/value - This paper considers simultaneously three different factors that influence maintenance float system performance: the number of spare units and the number of maintenance crews (which mean minimising the downtime effect) and the overhaul frequency (which means decreasing the number of failures). © Emerald Group Publishing Limited.

Abstract
In this paper a hybrid algorithm to solve Irregular Strip Packing problems is presented. The metaheuristic simulated annealing is used to guide the search over the solution space while linear programming models are solved to generate neighbourhoods during the search process. These linear programming models, which are used to locally optimise the layouts, derive from the application of compaction and separation algorithms. Computational tests were run using instances that are commonly used as benchmarks in the literature. The best results published so far have been improved by this new hybrid packing algorithm.

Abstract
In the 2005 Portuguese Parliament General Elections there were non-valid experiments of e-voting at five voting places and also through the Internet. Faculdade de Engenharia da Universidade do Porto audited such experiments. Relevant security, transparency, usability and accessibility evaluation criteria and sub-criteria were defined, and an auditing procedure based on AHP was established. This paper shortly presents the methodology used, the four e-voting systems and the main results of the overall experiment. The systems could be used successfully and were extremely popular with voters. However, more information to the citizens and to the officials involved in the e-voting process would be required for a valid election. The systems also need to be improved, for instance, to make sure that the number of votes electronically cast is the same as the number of voters that were validated and actually registered to vote at any particular site on the Election Day.

Abstract
This paper presents a time series whole clustering system that incrementally constructs a tree-like hierarchy of clusters, using a top-down strategy. The Online Divisive-Agglomerative Clustering (ODAC) system uses a correlation-based dissimilarity measure between time series over a data stream and possesses an agglomerative phase to enhance a dynamic behavior capable of concept drift detection. Main features include splitting and agglomerative criteria based on the diameters of existing clusters and supported by a. significance level. At each new example, only the leaves are updated, reducing computation of unneeded dissimilarities and speeding up the process every time the structure grows. Experimental results on artificial and real data suggest competitive performance on clustering time series and show that the system is equivalent to a batch divisive clustering on stationary time series, being also capable of dealing with concept drift. With this work, we assure the possibility and importance of hierarchical incremental time series whole clustering in the data stream paradigm, presenting a. valuable and usable option.

Abstract
Several discussions concerning the improvement of engineering students' learning process take place. The use of Active Learning tools is grabbing the attention of the pedagogical community as an answer to the recent education process requirements for the new century. A debut-mother project named PESC (To Project, To Undertake, To Know How to Achieve) aimed to fulfil these needs by involving students in a hands-on experience. Within this framework, the development of an industrial engineering and management game (IMAGE) was conducted. PESC initiative shows some similarities with CDIO (Conceiving-Designing-Implementing-Operating). However, the authors consider that this framework needs to be improved addressing other important attributes such as the capacity of identifying, evaluating and formulating problems beforehand. The argument is that PESC fulfils these requirements, based on the creation of multidisciplinary working teams under the students' leadership. Work organization and control were vital to the accomplishment of the proposed task. The project key success factors were the establishment of a direct communication and of ambitious assignments that would challenge the whole group. Moreover, detailed task scheduling, weekly meetings and weekly progress reports were implemented by the leaders. These steps induced team work, dynamism, competition and responsibility on the students, enabling the fulfilment of the ambitious deadlines.