基于Petri网化简技术的工作流模型合理性验证

随着工作流系统趋于大型化,使得可达图的验证技术对于大型模型进行验证时面临着状态空间爆炸的问题.因此,在过程验证之前,对大型模型进行化简是必要的.本文通过引入Petri网、Workflow Petri网和过程合理性定义,采用Petri网的两种化简技术,实现了工作流过程模型结构合理性验证过程.     

基于Petri网化简技术的工作流过程模型结构验证

目前,工作流系统向大型化发展,这使得基于可达图的验证技术在对大型模型进行验证时面临着状态空间爆炸的问题.因此,在过程验证之前,对大型模型进行化简是必要的.文中介绍两种化简规则.这些规则将一个大的Petri网化简为更小的Petri网,同时保持合理性属性,保证化简后的Petfi网和原有的Petri网具有相同的属性.介绍了Petri网、Workflow Petri网和过程合理性定义;讨论了针对Petri网的两种化简技术;提出了工作流过程模型结构合理性验证过程.     

一种基于Petri网化简的工作流过程语义验证方法

过程验证是保证工作流过程定义正确性的重要手段.针对过程定义中控制流、数据流和资源三维元信息相结合的冲突检测问题,研究了过程的语义验证方法.首先根据语义验证的需求,定义3DWFN网作为过程描述的形式化模型,然后基于该模型阐述了完成语义验证的化简规则.并通过与其他相关化简规则的比较,说明了这些规则在语义验证层面的优势.     

基于Petri网化简技术的工作流模型正确性研究

为了更有效地对工作流模型进行分析验证,提出了一种基于Petri网化简技术的工作流模型正确性验证方法。在对各种工作流模型验证技术深入研究的基础上,通过对非自由选择网结构活性和有界性的分析,给出了针对Petri网中非自由选择部分的分析方法。在保持活性和有界性的前提下,给出了将活的且有界的非自由选择部分转化为自由选择部分的转化方法,从而将非自由选择的Petri网验证问题转化为自由选择Petri网的验证问题。通过一个例子说明了如何使用该文提出的方法来验证模型的正确性。     

一种基于Petri网的工作流模型分解方法

工作流网的模型化简是模型有效分析的前提。在了解了工作流网及T-组件网相关定义的基础上,对工作流网的结构化简方法进行了分析,提出了一种简洁有效的工作流网模型的自由选择子网分解算法,给出了算法的过程同时也给出了算法的时间复杂度分析。最后,在算法的应用方面,将所提出的模型分解方法与目前常用的工作流网结构化简方法相结合,不仅可以有效提高模型化简的效率,而且还可以在模型化简的同时进行基于业务实例子网的模型分析。     

基于Petri网的工作流结构正确性化简验证方法

工作流技术是近年来在计算机应用领域发展最为迅速的新技术之一,但基于覆盖图的工作流网的结构正确性检查的实现过于复杂.本文在Aalst提出的基于Petri网的工作流网的控制流的正确性理论的基础上,提出了工作流网的正确性检查的化简规则及相应的化简算法,实现了对于正确结构的工作流网直接验证;对于错误结构的工作流网,输出其包含问题节点在内的子网结构,可以进一步通过覆盖图的方法确认问题节点,从而降低了工作流网正确性检查的复杂性.     

基于Petri网的工作流逻辑化简规则的矩阵表示

Petri网是一种很有效的模型描述语言,尤其适合描述工作流。给出了基于Petri网的工作流逻辑(WF_logic)化简规则,这里则借助矩阵及矩阵运算或矩阵上的初等变换来实现这些化简规则,进而用一个具体的实例进行了验证。     

基于Petri网的工作流模型合理性验证

工作流管理系统具有实时性、同步和异步操作等特点,其建模方法是成功实施工作流管理的关键,而工作流模型应该完整地支持工作流定义的概念,正确、高效地反应企业的经营组织过程,为确保工作流的正确运行,必须对工作流模型的合理性进行分析和研究,因此工作流的模型分析和优化成为工作流研究的一个重点[7]。该文从各种研究资料出发,利用工作流模型的合理性定义,给出基于Petri网的工作流模型的验证步骤和方法。     

基于Petri网的工作流模型

Petri网是一种很有效的模型描述语言，不仅能描述系统的结构特性，同时还能描述其动态特性，尤其适用于描述含有并行成分的系统，而工作流技术作为实现企业过程集成的有效手段，广泛用于各种场合。在简要介绍了Petri网和工作流基本知识的基础上，指出了基于Petri网的工作流模型的优点，讨论了将工作流模型转化为Petri网模型的基本原则，并且提出了一种扩展的Petri网模型作为一种工作流建模的工具，最后对基于Petri网的工作流模型进行了总结。     

基于Petri网的工作流过程建模

业务过程建模是整个工作流管理系统的基础,选择一种高效的建模技术对复杂多变的实际业务流程进行形式化表示对构建一个灵活的工作流管理系统起着至关重要的作用。本文利用了Petri网技术给业务过程建模,构造了一个灵活可分析的过程模型：首先介绍了相关的基于Petri网的工作流建模技术,接着描述了Petri网到工作流过程模型执行的映 射,然后给出了一个具体的基于Petri网建模方式的实例,最后利用随机Petri网和概率论的一些知识对该模型进行了时间性能分析。     

基于有色Petri网的经营过程建模

在经营过程重组（BPR）的过程中,利用仿真工具对经营过程建模与仿真分析,被认为是快速和顺利实施BPR的必要手段．目前大多数BPR支持工具局限于对过程的仿真,而Petri网则因其严格的数学定义和丰富的分析方法,不仅能够仿真过程的性能参数,还可以对过程的结构进行分析,从而在过程诊断和重组方案的设计中发挥重要作用．将有色Petri网应用于经营过程建模,可以较好地描述经营过程的不确定性、并发性和资源共享等问题,并解决模型中存在的冲突、死锁等问题,同时避免了普通Petri网过于复杂的缺点．     

Modeling and Analysis of Workflows Using Petri Nets

A workflow system, in its general form, is basically a heterogeneous and distributed information system where the tasks are performed using autonomous systems. Resources, such as databases, labor, etc. are typically required to process these tasks. Prerequisite to the execution of a task is a set of constraints that reflect the applicable business rules and user requirements.In this paper we present a Petri Net (PN) based framework that (1) facilitates specification of workflow applications, (2) serves as a powerful tool for modeling the system under study at a conceptual level, (3) allows for a smooth transition from the conceptual level to a testbed implementation and (4) enables the analysis, simulation and validation of the system under study before proceeding to implementation. Specifically, we consider three categories of task dependencies: control flow, value and external (temporal).We identify several structural properties of PN and demonstrate their use for conducting the following type of analyses: (1) identify inconsistent dependency specifications among tasks; (2) test for workflow safety, i.e. test whether the workflow terminates in an acceptable state; (3) for a given starting time, test whether it is feasible to execute a workflow with the specified temporal constraints. We also provide an implementation for conducting the above analyses.     

A methodology and tool environment for process analysis and reengineering

Most private and public organizations have recently turned their attention to the process by which they operate, to improve service and product quality and customer satisfaction. To support business process reengineering, methods and tools for process modeling and analysis are required. The paper presents the ARTEMIS methodology and associated tool environment for business process analysis for reengineering. In the ARTEMIS methodological framework, business processes are modeled as workflows and are analyzed according to an organizational structure perspective and an operational structure perspective. With these two perspectives, the analyst can plan reengineering interventions based on the degree of autonomy/dependency of organization units in terms of coupling, and the inter-process semantic correspondences, in terms of data and operation similarity, respectively. The ARTEMIS methodology and associated tool environment have been conceived and applied in the framework of the PROGRESS research project. In the paper, we report on a reengineering case study of this project involving the Italian Ministry of Justice.     

基于Petri网的工作流建模技术及在仿真中的应用

论文给出了将WFMC定义的工作流模型转化为工作流网络的完整框架,以及基于Petri网特性分析法的工作流网络仿真分析方法,并且用实例验证了该方法的可行性。     

一种基于Petri网的工作流模型分解方法

工作流网的模型化简是模型有效分析的前提.在了解了工作流网及T-组件网相关定义的基础上,对工作流网的结构化简方法进行了分析,提出了一种简洁有效的工作流网模型的自由选择子网分解算法,给出了算法的过程同时也给出了算法的时间复杂度分析.最后,在算法的应用方面,将所提出的模型分解方法与目前常用的工作流网结构化简方法相结合,不仅可以有效提高模型化简的效率,而且还可以在模型化简的同时进行基于业务实例子网的模型分析.     

Formal specification and state space analysis of an operational planning process

Formal models of business processes support performance and behavioural analysis of the processes for continuous improvement. Formal models are also useful in guiding the development of software tools to support the processes. This paper presents a formal model of the operational planning process used in an operational headquarters of the Australian Defence Force. The formal process model was developed using coloured petri nets (CPN or CP-nets). The constructed CPN model has allowed the planning process to be validated and analysed using simulation and state spaces. State space analysis was conducted using full state spaces and the sweep-line state space reduction method. The work of Lin Zhang was done while he was with the Command and Control Division of the Australian Defence Science and Technology Organisation.     

基于JBPM的服务动态编排及迁移方案

为了适应复杂环境下动态多变的业务需求,对以服务为核心的流程动态编排和再造提供支持,提出了基于JBPM工作流的流程动态编排与迁移方案,该方案分析了目前工作流在流程编排方面的局限性;结合柔性工作流的特点,给出了流程动态编排的模型,并对流程变更所产生的4类操作做了形式化的描述,通过对流程变更引发的流程进行迁移继而实现接续执行这一问题的研究,提出一种流程迁移算法。最后通过实例和性能测试工具验证了算法的可行性和高效性。     

Exterminating the Dynamic Change Bug: A Concrete Approach to Support Workflow Change

Adaptability has become one of the major research topics in the area of workflow management. Today's workflow management systems have problems dealing with both ad-hoc changes and evolutionary changes. As a result, the workflow management system is not used to support dynamically changing workflow processes or the workflow process is supported in a rigid manner, i.e., changes are not allowed or handled outside of the workflow management system. In this paper, we focus on a notorious problem caused by workflow change: the dynamic change bug (Ellis et al.; Proceedings of the Conference on Organizational Computing Systems, Milpitas, California, ACM SIGOIS, ACM Press, New York, 1995, pp. 10–21). The dynamic change bug refers to errors introduced by migrating a case (i.e., a process instance) from the old process definition to the new one. A transfer from the old process to the new process can lead to duplication of work, skipping of tasks, deadlocks, and livelocks. This paper describes an approach for calculating a safe change region. If a case is in such a change region, the transfer is postponed.     

Business processes—attempts to find a definition

Definitions of business process given in much of the literature on Business Process Management are limited in depth and their related models of business processes are correspondingly constrained. After giving a brief history of the progress of business process modeling techniques from production systems to the office environment, this paper proposes that most definitions are based on machine metaphor type explorations of a process. While these techniques are often rich and illuminating it is suggested that they are too limited to express the true nature of business processes that need to develop and adapt to today's challenging environment.