Showing papers on "Process architecture published in 2010"

Preserving correctness during business process model configuration

Abstract: A configurable process model captures a family of related process models in a single artifact. Such models are intended to be configured to fit the requirements of specific organizations or projects, leading to individualized process models that are subsequently used for domain analysis or solution design. This article proposes a formal foundation for individualizing configurable process models incrementally, while preserving correctness, both with respect to syntax and behavioral semantics. Specifically, assuming the configurable process model is behaviorally sound, the individualized process models are guaranteed to be sound. The theory is first developed in the context of Petri nets and then extended to a process modeling notation widely used in practice, namely Event-driven Process Chains.

From planning support systems to mediated planning support: a structured dialogue to overcome the implementation gap

Abstract: Planning support systems (PSSs) are intended to facilitate relevant steps in planning processes; however, the academic evaluation of PSSs reveals many bottlenecks precluding a widespread use of these systems. A central weakness is the lack of communication between PSS developers (focusing on technical issues) and potential PSS users. Other academic fields such as knowledge management and technological innovation recognised similar bottlenecks years ago. On the basis of methods proposed in these fields, a new process architecture for the development of a PSS is proposed. Through a dialogue in which PSS developers and potential users discuss and use the PSS, existing tools, instruments, and models are refined and improved to be more useful to their potential users. The focus shifts away from the development of a technically more sophisticated support system, towards a process of PSS development which is intertwined with the planning process itself. This process architecture is called mediated planning suppo...

Advances in Verification of Time Petri Nets and Timed Automata: A Temporal Logic Approach

Abstract: Specifying Timed Systems and Their Properties.- Petri Nets with Time.- Timed Automata.- From Time Petri Nets to Timed Automata.- Main Formalisms for Expressing Temporal Properties.- Model Generation and Verification.- Abstract Models.- Explicit Verification.- Verification Based on Satisfiability Checking.

Process Classification Frameworks

Abstract: The consistent structuring and modeling of behavioral descriptions is a prerequisite to any successful Business Process Management (BPM) initiative. This chapter presents a simple practical framework for aligning various concepts and representations of organizational behavior, which assists identifying appropriate model types. The framework is presented as a means to improve process modeling within BPM initiatives and as a guide to the development and documentation of process architectures. A health sector based example is provided in which the framework is used to align descriptions of organizational behavior to produce useful integrated behavioral reference models. The framework is also used to analyze model and process architecture completeness. The chapter concludes by noting current limitations of the framework and issues to be addressed through its further refinement.

Representations of Petri net interactions

Abstract: We introduce a novel compositional algebra of Petri nets, as well as a stateful extension of the calculus of connectors. These two formalisms are shown to have the same expressive power.

Colored timed Petri nets for modeling and analysis of cluser tools

Abstract: In this paper, a colored timed resource-oriented Petri net (CTROPN) is developed to model the cluster tools in semiconductor fabrication. It is structurally simple and concise, since each module in a cluster tool corresponds to a unique place in CTROPN. It is also powerful in modeling the qualitative and temporal behavior of the cluster tools with a single-blade or dual-blade robot. The initial transient behavior, steady-state behavior and the final transient behavior can all be investigated through a single model.

A behavioral similarity measure between labeled Petri nets based on principal transition sequences

Abstract: Being able to determine the degree of similarity between process models is important for management, reuse, and analysis of business process models. In this paper we propose a novel method to determine the degree of similarity between process models, which exploits their semantics. Our approach is designed for labeled Petri nets as these can be seen as a foundational theory for process modeling. As the set of traces of a labeled Petri net may be infinite, the challenge is to find a way to represent behavioral characteristics of a net in a finite manner. Therefore, the proposed similarity measure is based on the notion of so-called "principal transition sequences", which aim to provide an approximation of the essence of a process model. This paper defines a novel similarity measure, proposes a method to compute it, and demonstrates that it offers certain benefits with respect to the state-of-the-art in this field.

The downward-closure of petri net languages

Abstract: We show that the downward-closure of a Petri net language is effectively computable. This is mainly done by using the notions defined for showing decidability of the reachability problem of Petri nets. In particular, we rely on Lambert's construction of marked graph transition sequences -- special instances of coverability graphs that allow us to extract constructively the simple regular expression corresponding to the downward-closure. We also consider the remaining language types for Petri nets common in the literature. For all of them, we provide algorithms that compute the simple regular expressions of their downwardclosure. As application, we outline an algorithm to automatically analyse the stability of a system against attacks from a malicious environment.

Building an ontology and process architecture for engineering asset management

Abstract: Historically, asset management focused primarily on the reliability and maintainability of assets; organisations have since then accepted the notion that a much larger array of processes govern the life and use of an asset. With this, asset management’s new paradigm seeks a holistic, multi-disciplinary approach to the management of physical assets. A growing number of organisations now seek to develop integrated asset management frameworks and bodies of knowledge. This research seeks to complement existing outputs of the mentioned organisations through the development of an asset management ontology. Ontologies define a common vocabulary for both researchers and practitioners who need to share information in a chosen domain. A byproduct of ontology development is the realisation of a process architecture, of which there is also no evidence in published literature. To develop the ontology and subsequent asset management process architecture, a standard knowledge-engineering methodology is followed. This involves text analysis, definition and classification of terms and visualisation through an appropriate tool (in this case, the Protege application was used). The result of this research is the first attempt at developing an asset management ontology and process architecture.

Continuous petri nets: expressive power and decidability issues

Abstract: State explosion is a fundamental problem in the analysis and synthesis of discrete event systems. Continuous Petri nets can be seen as a relaxation of the corresponding discrete model. The expected gains are twofold: improvements in complexity and in decidability. In the case of autonomous nets we prove that liveness or deadlock-freeness remain decidable and can be checked more efficiently than in Petri nets. Then we introduce time in the model which now behaves as a dynamical system driven by differential equations and we study it w.r.t. expressiveness and decidability issues. On the one hand, we prove that this model is equivalent to timed differential Petri nets which are a slight extension of systems driven by linear differential equations (LDE). On the other hand, (contrary to the systems driven by LDEs) we show that continuous timed Petri nets are able to simulate Turing machines and thus that basic properties become undecidable.

A hybrid heuristic search algorithm for scheduling FMS based on Petri net model

Abstract: This paper presents a new scheduling method for a flexible manufacturing system (FMS) in a Petri net framework. Petri nets can concisely model multiple lot sizes for each job, the strict precedence constraint, multiple kinds of resources, and concurrent activities. To decrease the likelihood of rejecting the critical markings, our algorithm adopts an improved checking method for previous generated marking. To reduce the computation complexity, an elaborate scheme is applied, which performs A* search locally and backtracking search globally in the reachability graph of the Petri net. Some numerical experiments are carried out to demonstrate usefulness of the algorithm.

Virtual Data Warehouse Modeling Using Petri Nets for Distributed Decision Making

Abstract: A decision maker wants the pool of data at the finger tip while making the decision. In state of the art applications, decision making is no more a centralized process. Distribution of resources is a challenge before the system designers. Besides, for timely analyzing the distributed data, a robust query processing system along with the physical storage with schema definitions are also necessary. In the present state of business process skills, technologies, processes, applications and practices all are falling under the categories of competitive intelligence. In short BI aims to support better business decision-making. In this paper we propose an analytical model using Petri Net for distributed data management in a data warehouse to ease the OLAP (Online Analytical Processing) operations. Some of the properties of the model like safeness, boundedness, liveness and conservativeness are also verified..

Feature Petri Nets

Abstract: In software product line (SPL) engineering, formal modelling and verification are critical for managing the inherent complexity of systems with a high degree of variability The number of products in an SPL can be exponential in the number of features Therefore, the challenge when modelling SPL lies in analysing and verifying large, complex models efficiently, in order to ensure that all products behave correctly The choice of a system modelling formalism that is both expressive and well-established is therefore crucial In this paper we propose two lightweight extensions to Petri nets: Feature Petri Nets provide a framework for modelling and verifying software product lines; and Dynamic Feature Petri Nets provide additional support for modelling dynamic software product lines Keywords-software product lines; behavioural models; dynamic variability; Petri nets;

Petri Nets – A Mathematical Formalism to Analyze Chemical Reaction Networks

Abstract: In this review we introduce and discuss Petri nets - a mathematical formalism to describe and analyze chemical reaction networks. Petri nets were developed to describe concurrency in general systems. We find most applications to technical and financial systems, but since about twenty years also in systems biology to model biochemical systems. This review aims to give a short informal introduction to the basic formalism illustrated by a chemical example, and to discuss possible applications to the analysis of chemical reaction networks, including cheminformatics. We give a short overview about qualitative as well as quantitative modeling Petri net techniques useful in systems biology, summarizing the state-of-the-art in that field and providing the main literature references. Finally, we discuss advantages and limitations of Petri nets and give an outlook to further development.

Brief paper: new controllability condition for siphons in a class of generalised Petri nets

Abstract: Over the last two decades, a number of deadlock control policies based on Petri nets were proposed for flexible manufacturing systems (FMSs). As a structural object of a Petri net, siphons are widely used in deadlock control. For system of sequential systems with shared resources (S4R), the current deadlock control policies based on max or max′-controlled siphons tend to overly restrict the behaviour of a controlled system. The controllability conditions of a siphon are relaxed by a new concept called max″-controlled ones. We conclude that an S4R is live if all its siphons are max″-controlled. Compared with the existing ones, the proposed one is more general. Examples are given to illustrate it.

Synthesis of deadlock prevention policy using Petri nets reachability graph technique

Abstract: This paper proposes a subclass of generalized stochastic Petri net (GSPN) model, called TS3PR, which is modified the systems of simple sequential processes with resources (S3PR) with timed information. Based on the subclass of GSPN, a new deadlock prevention policy is developed by using reachability graph technique. The foundation of the new control policy is to manipulate all the dead states of the system nets. This study is able to change dead states into vanishing ones by additional immediate transitions. A live TS3PR model can then be obtained. It is worthwhile to notice that this study is different from adding additional control place policies in previous literature. Experimental results, indicate that our new control policy is with maximally permissive markings than conventional place-control ones. As a result, we can infer that our proposed control policy seems to be used in Petri nets deadlocked systems. To our knowledge, this is the first work that employs the additional transitions to obtain the deadlock prevention policy. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society

Formal Transformation from Sequence Diagrams to Coloured Petri Nets

Abstract: In this paper we define a formal strongly consistent transformation from UML2 sequence diagrams to coloured Petri nets (CPNs). We define the language of sequence diagrams (set of legal traces) and show how this is mapped onto an equivalent language of CPNs through formal transformation rules. The rules defined can be extended to consider modelling aspects such as stochastic and real-time behaviour. This work is part of a more general framework based on model driven transformations to validate UML models using Petri nets, and hence exploit existing Petri net analysis and verification tools for UML-based design.

Healthcare Modelling through Enterprise Architecture: A Hospital Case

Abstract: Enterprise Architecture (EA) is a strategic activity and planning tool for an enterprise, which facilitates decision-making by enabling a conceptual view of the enterprise The main objective of an EA approach is to define the layout of organizational components and relationships among them, in order to understand the integration of objects for further improvement In a healthcare context, EA has the potential to facilitate integrating healthcare units with business architecture Adapting appropriate tools for management analysis and decisions by healthcare management could have a significant impact on healthcare organizations such as in hospital goal achievement Process analysis within EA has the potential to improve understanding of healthcare functions leading to better healthcare-IT alignment The healthcare domain is significant due to its sensitivity of operations and human involvement Although improvement is welcomed in the healthcare arena, it is problematic and challenging to manage resources and service improvement is difficult due to the complexity of operations This research is intended to explore a process view and modelling of healthcare using EA Also, this research is based in a hospital in the United Kingdom The research aims to design and provide the insight of an EA approach to process architecture for healthcare-IT alignment In our case study, we analyzed healthcare organizational processes This paper conceptualizes this analysis and provides an overview of healthcare processes in the context of EA to improve healthcare management

Algebras of coloured/ Petri nets

Abstract: This book surveys more than ten years of research work about a framework of composable coloured Petri nets. This framework is organised around a core model of coloured Petri nets that can be extended with various features: control flow, synchronous communication, exceptions, threads, functions and time. Extensions are made in such a way that the underlying model of coloured Petri net is preserved and the usual analysis tools and techniques can still be used. However, specific verifications issues arise from the proposed approaches; we discuss these issues and propose solutions to enable for efficient verification. An implementation of the framework is also presented, as well as applications to the modelling and verification of security protocols, and to the modelling and analysis of biological regulatory networks in the context of developmental processes.

Diagnosis using unfoldings of parametric time Petri nets

Abstract: This paper considers the model of Time Petri Nets (TPNs) extended with time parameters and its use to perform on-line diagnosis of distributed systems. We propose to base the method on unfoldings. Given a partial observation, as a possibly structured set of actions, our method determines the causal relation between events in the model that explain the observation. It can also synthesize parametric constraints associated with these explanations. The method is implemented in the tool ROMEO. We present its application to the diagnosis of the example of a cowshed with pigs.

Composition of Petri nets models in service-oriented industrial automation

Abstract: In service-oriented systems, composition of services is required to build new, distributed and more complex services, based on the logic behavior of individual ones. This paper discusses the formal composition of Petri nets models used for the process description and control in service-oriented automation systems. The proposed approach considers two forms for the composition of services, notably the offline composition, applied during the design phase, and the online composition, related to the synchronization of Petri nets models on the fly. An experimental case study is used to illustrate the proposed composition approach.

Manufacturing System Modeling Using Petri Nets

Abstract: Petri nets which are used for modeling and analyzing complex systems that can be characterized as synchronous, parallel, simultaneous, distributed, resource sharing, nondeterministic and/or stochastic form a powerful modeling tool and are widely used today. In this study, fundamental concepts of Petri nets and their extensions are presented. Since the application area of Petri nets is wide, the subject is handled in the view of flexible manufacturing systems. A two stage modeling approach which combines the modeling power of stochastic Petri nets together with fuzzy sets is also presented. A numerical example is given to present how the proposed approach can be applied. We believe that this approach better represents both dimensions of uncertainty, stochastic variability and imprecision, in system modeling.

QPME 2.0: a tool for stochastic modeling and analysis using queueing Petri nets

Abstract: Queueing Petri nets are a powerful formalism that can be exploited for modeling distributed systems and analyzing their performance and scalability. By combining the modeling power and expressiveness of queueing networks and stochastic Petri nets, queueing Petri nets provide a number of advantages. In this paper, we present Version 2.0 of our tool QPME (Queueing Petri net Modeling Environment) for modeling and analysis of systems using queueing Petri nets. The development of the tool was initiated by Samuel Kounev in 2003 at the Technische Universitat Darmstadt in the group of Prof. Alejandro Buchmann. Since then the tool has been distributed to more than 100 organizations world-wide. QPME provides an Eclipse-based editor for building queueing Petri net models and a powerful simulation engine for analyzing the models. After presenting the tool, we discuss ongoing work on the QPME project and the planned future enhancements of the tool.

Robustness analysis of non-ordinary Petri nets for flexible assembly systems

Abstract: Non-ordinary controlled Petri nets (NCPNs) have the advantages to model flexible assembly systems in which multiple identical resources may be required to perform an operation. However, existing studies on NCPNs are still limited. For example, the robustness properties of NCPNs have not been studied. This motivates us to develop an analysis method for NCPNs. Robustness analysis concerns the ability for a system to maintain operation in the presence of uncertainties. It provides an alternative way to analyse a perturbed system without reanalysis. In our previous research, we have analysed the robustness properties of several subclasses of ordinary controlled Petri nets. To study the robustness properties of NCPNs, we augment NCPNs with an uncertainty model, which specifies an upper bound on the uncertainties for each reachable marking. The resulting PN models are called non-ordinary controlled Petri nets with uncertainties (NCPNU). Based on NCPNU, the problem is to characterise the maximal tolerable uncert...

Safeness for Object Nets

Abstract: In this paper we discuss the concept of safeness for Elementary Object Nets (EOS). Object nets are Petri nets which have Petri nets as tokens - an approach known as the nets-within-nets paradigm. Object nets are called elementary if the net system has a two levelled structure. The well known p/t nets can be considered as a special case of EOS. For p/t nets the concept of safeness means that there is at most one token on each place. Since object nets have nested markings there are different possibilities to generalise this idea for EOS. In this paper we define different variants of EOS safeness, discuss their relationships, show that they all coincide for p/t-like EOS, and address the complexity of well known Petri net problems like reachability and liveness for this new class of object nets.

INCOME2010 - a Toolset for Developing Process-Oriented Information Systems Based on Petri Nets

Abstract: Petri nets are widely accepted as a process modeling technique with formal semantics and mathematical foundation. They are well suitable for modeling (business) processes in executable form and for analyzing process models through simulative validation and formal verification. Nevertheless, there are currently only a small number of Petri net based tools available for developing process-oriented information systems, which have gained importance in recent years because of the awareness that business processes are one of the key success factors for organizations. In this paper we survey the project INCOME2010 aiming at developing an open source software toolset that facilitates the development of process-oriented information systems. It provides functionalities for modeling, analyzing, executing, and monitoring (business) processes using variants of high-level Petri nets and concepts of Service-Oriented Architecture.