Maria Teresa Pilloni

Modelling and simulation of a bottling plant using hybrid Petri nets

In this paper we use First–Order Hybrid Petri nets (FOHPN), an hybrid model that combines fluid and discrete event dynamics, to model the concurrent activities of manufacturing systems. In particular we consider an existing mineral water bottling plant and we show how the FOHPN model is extremely suited to describe the high-throughput production lines, that are one of the main components in the considered plant. Some variations with respect to the previous definition of the FOHPN model are also introduced here to better describe the behavior of the conveyor lines. Finally, we show that, thanks to the fluid approximation of some discrete-event dynamics, the considered plant may also be efficiently simulated using FOHPN. This also enabled us to identify, among the most commonly used configurations of the plant, which are the optimal working conditions in terms of maximal throughput and net profit.

Modeling of a bottling plant using hybrid Petri nets

In this paper we deal with the problem of modeling a bottling plant using First-Order Hybrid Petri nets. The model we use is an hybrid model that combines fluid and discrete event dynamics and enables us to simulate the dynamic concurrent activities of manufacturing systems. It also provides a modular representation of the considered plant, thus allowing one the bottom-up construction of models for large scale systems.

A multi-criteria fuzzy method for selecting the location of a solid waste disposal facility

Facility location is a multi-criteria decision process that has important operational and economic impacts and that typically involves uncertainty and vagueness of evaluations. A fuzzy-based method supporting preliminary decision-making about siting solid waste incinerators is proposed building on a structured classification of criteria for location selection developed from the existing literature. The application to a case study revealed the advantages of the methodology. The work intends to provide a general and comprehensive taxonomy of decision criteria that may be adapted to various facility location problems together with a fuzzy inference process that is useful for companies and public administration institutions looking for rigorous but relatively simple decision-making tools in uncertain environments. Future research will compare the developed method with the most common tools for making location decisions. The approach will be then extended to different kinds of facilities.

Analysis of End-of-Life Vehicle Processes: A Case Study in Sardinia (Italy)

The present work aimed at giving a review of the end-of life phase for motor vehicles, providing accurate process modeling, indicating critical aspects, and finally suggesting improvements. For the study, one of the principal dismantler in Sardinia (Italy) was considered. The main innovation is the bottom-up approach to the problem; this was carried out by field observing the process activities and sharing the criticalities identification with the actors. The study has confirmed that the simplicity of disassembling the components and the ease of identification of the different materials to be separated is fundamental for an efficient dismantling of motor vehicles. It is finally crucial that the dismantling processes, being highly complicated, mainly involve the same manufacturers.