Process architecture

About: Process architecture is a research topic. Over the lifetime, 4876 publications have been published within this topic receiving 104171 citations.

Petri Net Based Deadlock Prevention Approach for Flexible Manufacturing Systems

Abstract: A deadlock prevention strategy for flexible manufacturing systems is developed based on Petri nets and their structural analysis. The concept of elementary siphons is proposed, it is a class of SMS (strict minimal siphons) with a smaller cardinality, particularly in the Petri net models of large-scale systems. By adding a control place for each elementary siphon to make it never be emptied, deadlocks can be prevented for a special class of Petri nets, namely S 3 PR. That means not all SMS need to be considered when ensuring no siphon loses its tokens. For S 3 PR, An approach is proposed for finding elementary siphons and SMS. Compared with the existing methods that control all SMS in a Petri net, the deadlock prevention policy has at least three advantages: 1) only a smaller number of SMS need to be controlled, hence the deadlock-freeness or live Petri net model obtained has less additional places and arcs; 2) not need to compute the set of siphons beforehand; and 3) this policy is more suitable for large-scale Petri nets. These methods are illustrated with an example.

Synthesis of ladder diagrams from Petri nets controller models

Abstract: This paper addresses the problem of automated synthesis of ladder diagrams for programmable logic controllers (PLC). The programs are obtained from control specifications expressed as timed interpreted Petri nets (TIPN). The approach herein presented allows to rapidly synthesize correct programs for PLC; it is based on a set of simple translation rules that produces a ladder diagram (LD) from a TIPN. Moreover this set of rules was coded into a program to automate this process.

Feature Nets: behavioural modelling of software product lines

Abstract: Software product lines (SPLs) are diverse systems that are developed using a dual engineering process: (a) family engineering defines the commonality and variability among all members of the SPL, and (b) application engineering derives specific products based on the common foundation combined with a variable selection of features. The number of derivable products in an SPL can thus be exponential in the number of features. This inherent complexity poses two main challenges when it comes to modelling: firstly, the formalism used for modelling SPLs needs to be modular and scalable. Secondly, it should ensure that all products behave correctly by providing the ability to analyse and verify complex models efficiently. In this paper, we propose to integrate an established modelling formalism (Petri nets) with the domain of software product line engineering. To this end, we extend Petri nets to Feature Nets. While Petri nets provide a framework for formally modelling and verifying single software systems, Feature Nets offer the same sort of benefits for software product lines. We show how SPLs can be modelled in an incremental, modular fashion using Feature Nets, provide a Feature Nets variant that supports modelling dynamic SPLs, and propose an analysis method for SPL modelled as Feature Nets. By facilitating the construction of a single model that includes the various behaviours exhibited by the products in an SPL, we make a significant step towards efficient and practical quality assurance methods for software product lines.

Model Checking of Persistent Petri Nets

Abstract: In this paper we develop a model checking algorithm which is fast in the size of the system. The class of system models we consider are safe persistent Petri nets; the logic is S4, i.e. prepositional logic with a ‘some time’ operator. Our algorithm does not require to construct any transition system: We reduce the model checking problem to the problem of computing certain Parikh vectors, and we show that for the class of safe marked graphs these vectors can be computed — from the structure of the Petri net — in polynomial time in the size of the system.

Constructs for Modeling Information Systems with Petri Nets

Abstract: This paper is concerned with elementary and high-level Petri nets (coloured Petri nets and predicate/transition nets) and their utility for conceptual modeling of information systems. Particular features of existing net classes are discussed and additional net constructs are proposed for that purpose. Adequate conceptual models, i.e., models which reflect an intended view of an information system without any strange or artifical elements are best obtained if the following features are available to the modeler: (i) places have finite capacities (bounded places), (ii) arc expressions denote sets of variable cardinality, (iii) exclusive and shared use of side-conditions can be specified, (iv) terms denoting the set of all entities of a current marking or a specified subset thereof can be used in transition expressions, (v) static properties can be specified in state-oriented terms and impose restrictions on the dynamic properties specified in transition-oriented terms. The paper presents examples of each one of these desirables features and discusses them against the existing high-level Petri net classes or shows how they can be provided without resorting to so-called extensions.