Multicriteria Model of Preventive Maintenance

It is extremely important to guarantee that the performance levels required by productive systems can be maintained. As well, it is essential to assure the quality of process outputs. For this reason, preventative maintenance has become a very useful instrument to gain a competitive edge. In maintenance decisions, there are some contradictory criteria or points of view that are vital and must to be looked at simultaneously. Optimization approaches are not so useful in this situation, since usually no decision or solution exists which is the best from all points of view at the same time. So, in this context, the multicriteria decision aid (MCDA) approach is very important, allowing not only for the trade-off of multiple factors, but also taking in account the preference structure of the decision-maker with respect to these contradictory criteria. To address this issue, this article proposes a multicriteria decision aid model to support the decision-maker in the choice of times for preventative maintenance. The model preserves some important concepts from the classic models of component replacement and improves an existing multicriteria model, by taking criterion downtime into consideration, making a more appropriate treatment possible than the previous model for situations in cases where repair time cannot be ignored

Identificación del índice de vulnerabilidad territorial a partir de modelos jerárquicos y heurísticos aplicando SOA

Auxiliar de InvestigaciónEn el proyecto se realiza el diseño y desarrollo de 4 servicios web implementando los modelos de toma de decisión (AHP, AHP FUZZY, ELECTRE y PROMETHEE), encargados de procesar datos obtenidos en campo en la primera fase del proyecto que se realizó a través de encuestas, formatos de entrevistas, talleres y metodologías de análisis. Los datos se procesaran de acuerdo al modelo de toma de decisión seleccionado, generando como resultado final un indicador de vulnerabilidad territorial.PregradoIngeniero de Sistema

Modelos multicritério de apoio a decisão para manutenção preventiva baseados no método Promethee

Alvo de grandes mudanças, com o avanço tecnológico das máquinas e equipamentos, a manutenção tem se tornado um diferencial para as empresas que desejam permanecer competitivas, com baixos custos e com uma elevada capacidade produtiva. Para isso, tornase essencial o estudo científico e a criação de modelos formais capazes de dar um tratamento seguro para problemas típicos do ambiente de manutenção, os quais reclamam decisões, cujas conseqüências são muito importantes, os resultados não triviais e, não raras vezes, muitos dos parâmetros são desconhecidos. Nesse contexto, o trabalho vem trazer a sua colaboração, na proposição de novos modelos e técnicas, a fim de solucionar tais problemas. E mais: proporciona o apoio multicritério na elaboração de políticas de manutenção, ensejando ao decisor estabelecer um período entre substituições de equipamentos, tendo em vista os valores de confiabilidade e de custo de manutenção por unidade de temp

Electre tri method used to storage location assignment into categories

Day after day, the importance of a company having an efficient storage location assignment system increases. Moreover, since products have different warehouse costs and customers' requirements are also different, it is important to sort products in order to adopt strategies for inventory management that are appropriate for each product. However, adopting a policy for each product is not applicable in the real world. Therefore, companies usually categorize products into classes and thereafter adopt specific inventory management policies. Given this situation, this paper puts forward the arguments for adopting a multi-criteria method, Electre TRI, to sort products that both considers criteria relating to the characteristics of a product as to its physical location in the warehouse and the criteria that are important for inventory strategies, such as, for example, the profitability of each unit held in storage

Using the Efficient Frontier to Obtain the Best Solution for the Storage Location Assignment Problem

The main variables that influence the efficiency of a warehouse are the use of space and the order picking distance. In the literature, there are proposals to add the costs with space and order picking in order to evaluate each alternative for storage location assignment. However, there were problems with the adoption of this methodology, including difficulties in determining the costs and tradeoffs between them. These difficulties can result in solutions that are suboptimal. Based on these facts, this paper proposes a class-based storage process and storage location assignment by a cube-per-order index (COI) that analyzes the space required and the total order picking distance by Pareto-optimal calculations. The efficient frontier possibilities allow the reduction of the set of alternatives, and the DM can analyze only the alternatives on efficient frontier