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Nowadays, the collection of separated solid waste for recycling is still an expensive process, specially when performed in large-scale. One main problem resides in fleet-management, since the currently applied strategies usually have low efficiency. The waste collection process can be modelled as a vehicle routing problem, in particular as a Team Orienteering Problem (TOP). In the TOP, a vehicle fleet is assigned to visit a set of customers, while executing optimized routes that maximize total profit and minimize resources needed. The objective of this work is to optimize the waste collection process while addressing the specific issues around fleet-management. This should be achieved by developing a software tool that implements a genetic algorithm to solve the TOP. We were able to accomplish the proposed task, as our computational tests have produced some challenging results in comparison to previous work around this subject of study. Specifically, our results attained 60% of the best known scores in a selection of 24 TOP benchmark instances, with an average error of 18.7 in the remaining instances. The usage of a genetic algorithm to solve the TOP proved to be an efficient method by outputting good results in an acceptable time.

This work presents a decision support system for route planning of vehicles performing waste collection for recycling. We propose a prototype system that includes three modules: route optimization, waste generation prediction, and multiple-criteria decision analysis (MCDA). In this work we focus on the application of MCDA in route optimization. The structure and functioning of the DSS is also presented. We modelled the waste collection procedure as a routing problem, more specifically as a team orienteering problem with capacity constraints and time windows. To solve the route optimization problem we developed a cellular genetic algorithm. For the MCDA module, we employed three methods: SMART, ValueFn and Analytic Hierarchy Process (AHP). The decision support system was tested with real-world data from a waste management company that collects recyclables, and the capabilities of the system are discussed.

-The design of production and logistic systems is a process of managing both technical and organizational variants in order to identify the best solution for a given system. This is a very well-known industrial engineering issue, where the objectives for designing such a system have been changing over the last decades. Former approaches were concerned about material handling costs only but more recent works include re-layout and product mix costs, together with a great concern on processes -high service levels, optimal scheduling policies, setup times and costs, etc. Nowadays, the rapid technological progress and the associated competitive problems lead to a great need of fast and successful solutions to deal with continuous change (re-design) of the currently used industrial systems. Flexibility, modularity, efficiency and robustness are generally highly desired system properties. For general design of industrial systems, three basic types of software tools are used: Computer Aided Design, Simulation and Information Systems. These tools help on improving the utilization of system resources like equipment, manpower, materials, space, energy, information, etc. Nevertheless these three types of software tools have been used with low levels of integration. This absence of an adequate data connection and integration of outputs cause time delays in the design process, duplication of work and could also be a source of errors. In this work, Production Systems Design software tools integration possibilities are discussed and a unified system architecture solution, implemented on AutoCAD (layout design), Witness (Simulation) and MS-Access (Information Systems) is presented. The aim is to focus on the need of data coherence between different software tools, exploring ways of dealing with data diversity and assuring valid and efficient solutions. MS-Access supports the specification of the system and data exchange between Witness and AutoCAD. Based on the database specification, our application automatically generates simulation programs and also different spatial patterns of project layouts. These tasks are implemented in Visual Basic code. Iteratively the results from the simulations are used to improve AutoCAD layouts and AutoCAD layouts are used in new simulations. The use of our application, in the examples showed in this paper, proved to get quick, valid and efficient solutions.