The optimization problem based on alternatives aggregation Petri nets as models for industrial discrete event systems

Abstract

The construction, set-up and operation of many systems of interest in sectors such as industry, supply chains and communications are complex processes, which may require significant investment of resources. For this reason, the automation of the decision making for achieving the best design and operation of such systems, which may be regarded as discrete event systems (DESs), constitutes an active research field. In this paper, we present a methodology to cope with this process in an efficient way, optimizing not only the behaviour of the DES but also its structure. This kind of problem is usually associated with the so-called combinatorial explosion, since the number of alternative configurations for the DES might be huge. We present an improved algorithm to transform a set of alternative Petri nets, representing alternative structural configurations, into a more compact model called an alternatives aggregation Petri net. In real decision-making problems, where the different alternative structural configurations may share common subnets, this compact model may allow the development of a much more efficient optimization problem than the classic approach of ‘divide and conquer’. The achievement of this objective is performed by developing a single and compact model for all of the alternative structural configurations of the DES and the simulation of the most promising of them. In this paper, the mentioned methodology is introduced and its advantages and drawbacks are described in relation with the classic approach.

Equivalent and Efficient Optimization Models for an Industrial Discrete Event System with Alternative Structural Configurations

“…Usually, in the design process of a DES, some of the degrees of freedom that should be solved by the designers refer to structural features of the system [18], while some others can be related to the system's behavior. For example, the layout of the components of the system is a feature related to its structure.…”

Control of Discrete Event Systems by Means of Discrete Optimization and Disjunctive Colored PNs: Application to Manufacturing Facilities

“…In order to be able to define new formalisms aiming to describe discrete event systems with alternative structural configurations, a previous step with the definition of a set of objects that generalize the idea of set of alternative Petri nets showing mutually exclusive evolution will be introduced. The appropriate concept is that of set of exclusive entities, which are formally introduced in the following [34]. .…”

Predictive monitoring of production line efficiency

“…In particular, the model is used to obtain an insight into the future behaviour of key variables. This information can facilitate the effective ergonomic (re)design and its optimization (del Rio Vilas et al 2013, Latorre et al 2013) but can also be used in the context of real-time operational management (Curcio et al 2007, Mujica et al 2010.…”