Process architecture

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

Analysis of asynchronous concurrent systems by timed petri nets

Abstract: This thesis is concerned with the modeling and performance analysis of systems which consist of concurrently acting components, an example of which is an asynchronous pipelined processor. The work is divided into two parts. In the first part, a suitable model is developed for describing the structure of asynchronous concurrent systems. In conventional automata theory, the finite-state machine model is used to describe the behavior of systems; the problem with this is that a large number of states results when practical systems are modeled. In this thesis, each system component is modeled as a finite-state machine, and a system is viewed as an ensemble of interconnected finite-state machines. This has the advantage that the size of a system model grows linearly rather than exponentially with the number of system components. A subclass of Petri nets known as SMD (State Machine Decomposable) Petri nets is identified in order to formalize the notions of finite-state machines and their inter-connection. For convenience, systems of interest are divided into two broad categories: (a) deterministic, or decision free, (b) non-deterministic, or systems with decisions. SMD Petri nets are used to model both classes of systems; in addition, a subclass of Petri nets known as LSP Petri nets is used to model those deterministic systems that cannot be modeled by SMD Petri nets. The second part of the thesis is concerned with finding the computation rate of activities in real-world asynchronous concurrent systems. Practical systems are constructed from devices which have a finite speed of operation. Since Petri nets do not have time parameters as part of their definition, they can model the structure of systems but cannot be used to study their computation rate. The definition of Petri nets is augmented to model the speed of operation of a device in a system by assuming that the corresponding activity in the Petri net has a finite, non-zero time duration. The resulting nets are termed timed Petri nets, and methods are given for finding the computation rate of activities in times SMD and LSP Petri nets. The results are applied to the analysis of several asynchronous systems drawn from areas within and outside the domain of computer systems.

Verification of Workflow Nets

Abstract: Workflow management systems will change the architecture of future information systems dramatically. The explicit representation of business procedures is one of the main issues when introducing a workflow management system. In this paper we focus on a class of Petri nets suitable for the representation, validation and verification of these procedures. We will show that the correctness of a procedure represented by such a Petri net can be verified by using standard Petri-net-based techniques. Based on this result we provide a comprehensive set of transformation rules which can be used to construct and modify correct procedures.

Discrete, continuous, and hybrid Petri Nets

Abstract: Petri Nets were introduced and still successfully used to analyze and model discrete event systems especially in engineering and computer sciences such as in automatic control. Recently this discrete Petri Nets formalism was successfully extended to continuous and hybrid systems. This monograph presents a well written and clearly organized introduction in the standard methods of Petri Nets with the aim to reach an accurate understanding of continuous and hybrid Petri Nets, while preserving the consistency of basic concepts throughout the book. The book is a monograph as well as a didactic tool which is easy to understand due to many simple solved examples and detailed figures. In its second completely reworked edition various sections, concepts and recently developed algorithms are added as well as additional examples/exercises.

Formalization and verification of event-driven process chains

Abstract: For many companies, business processes have become the focal point of attention. As a result, many tools have been developed for business process engineering and the actual deployment of business processes. Typical examples of these tools are Business Process Reengineering (BPR) tools, Enterprise Resource Planning (ERP) systems, and Workflow Management (WFM) systems. Some of the leading products, e.g. SAP R/3 (ERP/WFM) and ARIS (BPR), use Event-driven Process Chains (EPCs) to model business processes. Although the EPCs have become a widespread process modeling technique, they suffer from a serious drawback: neither the syntax nor the semantics of an EPC are well defined. In this paper, this problem is tackled by mapping EPCs (without connectors of type ∨) onto Petri nets. The Petri nets have formal semantics and provide an abundance of analysis techniques. As a result, the approach presented in this paper gives formal semantics to EPCs. Moreover, many analysis techniques are available for EPCs. To illustrate the approach, it is shown that the correctness of an EPC can be checked in polynomial time by using Petri-net-based analysis techniques.

Free choice Petri nets

Abstract: 1. Introduction 2. Analysis techniques for petri nets 3. S-systems and T-systems 4. Liveness in free choice 5. The coverability theorems 6. The rank theorem 7. Reduction and synthesis 8. Home markings 9. Reachability and shortest sequences 10. Generalizations Index List of symbols List of main results.