The facility layout problem approached using a fuzzy model and a genetic search

2005

The problem of facility layout design is discussed, taking into account the uncertainty of production scenarios and the finite production capacity of the departments. The uncertain production demand is modelled by a fuzzy number, and constrained arithmetic operators are used in order to calculate the fuzzy material handling costs. By using a ranking criterion, the layout that represents the minimum fuzzy cost is selected. A flexible bay structure is adopted as a physical model of the system while an effective genetic algorithm is implemented to search for a near optimal solution in a fuzzy contest. Constraints on the aspect ratio of the departments are taken into account using a penalty fun…

A multi-objective approach to solid waste management

2010

The issue addressed in this paper consists in the localization and dimensioning of transfer stations, which constitute a necessary intermediate level in the logistic chain of the solid waste stream, from municipalities to the incinerator. Contextually, the determination of the number and type of vehicles involved is carried out in an integrated optimization approach. The model considers both initial investment and operative costs related to transportation and transfer stations. Two conflicting objectives are evaluated, the minimization of total cost and the minimization of environmental impact, measured by pollution. The design of the integrated waste management system is hence approached i…

Le tecniche di ragionamento approssimato nella gestione dei container terminal

2004

MInimizing earliness and tardiness costs by ant system approach

2005

The performance of production systems, which are more and more client oriented, strongly depends on the punctuality in the delivery of orders. However, management policies of manufacturing systems have a tendency of reducing batch dimensions which, sometimes, is reduced to a single job. The reason for this tendency is to reduce quantities of stock and to satisfy the customer’s requirements. It is the Just-in-Time approach, in which the production of a job is scheduled after the acquisition of an order, on the basis of the due date and the actual production capacity of the system. In the present paper, a manufacturing system characterized by a bottleneck station is considered. A set of jobs …

Logistica delle merci La rivoluzione del container

2005