A timed Petri net based approach for the design of industrial processes

The effective design of industrial processes represents a key asset to compete and to create a sustainable value for each company. Such a complex issue needs to integrate technological, economical, environmental and safety constraints and opportunities to be mixed together through a win-win strategy. The development of useful, easy-use and flexible approaches to analytically support both the researchers and the practitioners in the industrial process design, development and simulation is expected and strongly encouraged. Purpose This paper focuses on the design and simulation of industrial processes adopting a timed Petri net based approach. Considering a product flowing the manufacturing/assembly area and visiting a set of resources according to its working cycle, a timed Petri net design strategy is presented together with the dynamic analysis of the net to predict the process key performances. The resource peculiarities, e.g. availability and conflicts, are, further, considered. A realistic case study, taken from the automotive sector, is, finally, presented, to exemplify the proposed approach. Methodology and approach Starting from an overview of Petri nets and their fundamentals, the paper investigates an approach for their effective adoption in the industrial process design. An industrial and operative perspective is adopted, while a realistic case study is proposed to highlight the applicability of such a tool in common operative contexts. The manufacture process of high value components for sport-cars requiring dedicated resources and auxiliary devices is presented and fully discussed. Starting from the production process analysis, to identify both the production features and the required resource characteristics, the timed Petri net is designed adopting the most suitable approach, i.e. physical vs. functional. Given the net, its simulation and analysis is faced to obtain useful indices about the production process performances, e.g. throughput, required resources, resource availability, waiting times and buffer dimensions, etc. Such analysis outcomes represent useful guidelines to drive possible design or re-design actions. Originality Petri nets and, particularly, timed Petri nets represent a diffuse modeling language for the description of event-driven distributed systems. Their adoption in the automation control theory is known and widely discussed by the literature, together with a wide set of customization opportunities. On the contrary, minor attention is paid to study the applicability of this modeling language in the industrial sector to support the design of manufacturing and assembly processes with a deep focus on the operative context features and on the effects in terms of production efficiency, times and costs. This paper tries to overcome such a weakness focusing on the applicability of timed Petri nets to the industrial sector. Both the approach input and output are oriented to drive the process design, while the realistic case study exemplifies the opportunities of applying a timed Petri net based approach to the design of the production system for automotive high-value parts.