Abstract
The performance of a company depends on its strategic decisions but also on the efficiency of how those decisions are implemented by all of its sectors. In any company there are different sectors or groups, probably physically distributed, with different levels of autonomy, each one controlling local resources and interacting with the others. Many companies use simulation software to analyze critical sectors based in a number of scenarios, in order to estimate the efficiency of the different configurations. The process of simulate alternative solutions can be time consuming. Depending on the software used it may be necessary to generate new simulation models for each solution, develop new applications or change existing ones. This paper describes a simulation framework where each element is modelled using the discrete-event approach and interoperability between elements is achieved by the combination of web services and Agent-based modelling and simulation (ABMS). The use of ABMS in this framework provides an easier way to evaluate alternative solutions. Each sector or group is an agent that can be added or removed from the model to build different configurations. A multi-hierarchical simulation executive is proposed in order to enable the use of different time intervals in each level. This increases the autonomy of the simulation agents and promotes the use of parallel or distributed solutions.

Abstract
The evolution in demand is leading industry market to seek for product orders in smaller lots and shorter deadlines. A need therefore arises to adapt industry production to these market changes. A portuguese plumbing and bath accessories company decided to study a new organization layout for its multi-site production plant. The objective was to evaluate different organization scenarios in order to rationalize the floor layout and reduce costs. This Paper presents a study to evaluate different scenarios for a multi-site production plant using the Arena simulation software tool. The simulation model uses VBA (Visual Basic for Applications) to dynamically generate the simulation model. The product data is read from Excel spreadsheets or text files. Autocad is used for defining the plant layout and generating the working center coordinates. The Autocad drawing is used as the simulation background allowing the display of a realistic scaled animation.

Abstract
This paper is concerned with the use of simulation as a decision support tool in maintenance systems, specifically in MFS (Maintenance Float Systems). For this purpose and due to its high complexity, in this paper the authors propose a flexible way to develop typical MFS models, for any number of machines in the workstation, spare machines and maintenance crews. Arena simulation language is used to understand a specific MFS, create the corresponding MFS model and analyze most common performance measures.

Abstract
This paper is concerned with the use of simulation as a decision support tool in maintenance systems, specifically in MFS (Maintenance Float Systems). For this purpose and due to its high complexity, in this paper the authors explore and present a possible way to construct a MFS model using Arena simulation language, where some of the most common performance measures are identified, calculated and analysed. Nevertheless this paper would concentrate on the two most important performance measures in maintenance systems: system availability and maintenance total cost. As far as these two indicators are concerned, it was then quite clear that they assumed different behavior patterns, specially when using extreme values for periodic overhauls rates. In this respect, system availability proved to be a more sensitive parameter.

Abstract
This paper is concerned with the use of simulation as a decision support tool in maintenance systems, specifically in MFS (Maintenance Float Systems). For this purpose and due to its high complexity, in this paper the authors explore and present a possible way to construct a MFS model using Arena simulation language, where some of the most common performance measures are identified, calculated and analysed.

Abstract
A method for the recovery and fractionation of whey proteins from a whey protein concentrate (80%, w/w) by hydrophobic interaction chromatography is proposed. Standard proteins and WPC 80 dissolved in phosphate buffer with ammonium sulfate 1 M were loaded in a HiPrep Octyl Sepharose FF column coupled to a fast protein liquid chromatography (FPLC) system and eluted by decreasing the ionic strength of the buffer using a salt gradient. The results showed that the most hydrophobic protein from whey is alpha-lactalbumin and the less hydrophobic is lactoferrin. It was possible to recover 45.2% of beta-lactoglobulin using the HiPrep Octyl Sepharose FF column from the whey protein concentrate mixture with 99.6% purity on total protein basis.