UML活动图描述工作流模型的执行语义

UML是软件工程中广泛应用的建模语言,但其主要问题是缺少严格的形式化语义,因而描述的模型容易产生歧义.根据UML活动图的语法和工作流系统的特点,为UML活动图定义了一种执行语义.基于时间转变系统模型,将工作流系统的执行描述为时间转变和数据转变两个交替进行的过程.时间转变描述时间的前进,数据转变修改工作流案例的状态,这种语义比层次状态图具有更强的描述并行的能力,比Petri网和进程代数更适合描述工作流模型.     

工作流模型及其形式化描述

工作流是一个业务过程的全部或部分自动执行．为了实现工作流管理功能，我们必须将业务过程从现实世界中抽象出来，并用一种形式化方法对其进行描述，其结果称为是工作流模型．该文主要讨论工作流模型及其形式化描述问题．基于对现实世界业务过程的分析，该文提出一个三维工作流模型，它包含3个子模型：组织模型、数据模型和过程模型，分别从不同的侧面描述工作流的各种属性．文中详细论述各个子模型及其相互关系，并给出三维工作流模型的形式化描述．     

一种基于ECA规则的Web Service工作流模型的研究

工作流技术的深入应用要求工作流管理系统增强Web服务功能,基于Petri网工作流过程模型存在无法表述状态变迁过程或状态变迁边缘时刻事件的缺陷.给出了基于ECA规则Web Service工作流模型形式化定义,基于ECA规则的过程模型以事件推动工作流实例的执行,通过严格定义事件的语义来保证工作流的正确执行和监控并支持工作流在运行中修改实例.     

一种新的柔性化工作流建模方法的研究与应用

在分析工作流柔性特点的基础上,描述了一种改进的工作流模型,提供了对柔性工作流模型形式化描述和工作流柔性的支持能力,从而能够在执行过程中动态更改工作流逻辑,适应企业业务流程的快速变化。     

基于Pi演算的工作控制流模式研究

工作流模式指在工作流过程模型中反复出现的过程基本构造,是衡量工作流建模语言在控制流方面的表达能力和适用性的重要标准。本文以Pi演算作为工作流形式化的基础,对当前流行的一些工作流模式进行详细的描述,并提出一些应用实例。结果表明,该语言不仅能很好地支持工作流模式,而且具有建模。。简洁、准确的特点。     

支持服务协作的工作流元模型和建模语言

当前支持Web服务的建模语言存在着复杂度高、互操作困难和缺乏对服务协作关系的有效支持等不足。结合面向服务工作流的服务协作需求，通过扩展工作流管理联盟的相关理论，定义了面向服务工作流的过程定义元模型，并建立了其形式化模型。通过扩展XPDL定义了一种互操作性好、支持服务协作的面向服务工作流建模语言（SoXPDL）。     

基于时序描述逻辑的UML顺序图形式化研究

在统一建模语言（UML）规范中顺序图的语义是以自然语言的形式描述的,是一种半形式化的语言,不能对系统的交互行为进行形式化分析及论证.针对UML顺序图缺乏精确的形式化描述问题,根据顺序图的时序特征,提出了增加交互操作符的UML顺序图的六元组形式化方法.对描述逻辑进行时序扩展,得到可表示动态和时序语义的形式化规范——时序描述逻辑.应用时序描述逻辑的时态算子得到时序描述逻辑语义形式的UML顺序图.用UML顺序图描述完整的C语言执行过程,将其形式化描述,实验结果表明,这种方法是可行的.     

一种软件过程建模语言SPML的设计

本文提出了一个具有丰富语义、灵活的、可扩展的、形式化的软件过程建模语言SPML。它提供了两个不同抽象层次的描述语言以满足不同用户的需求。高抽象层次的语言SPML／H能够较全面地描述软件过程,具有良好的易用性;低抽象层次的语言SPML／L可以描述规则等,适合描述软件过程的细节。SPML／H还能够被逐步地变换成SPML／L,保证了软件过程模型可以在一个共同的形式化基础上被分析和运作。最后通过一个实例说明过程建模语言的有效性。     

一种改进的软件测试流程实例的描述方法

提出了测试流程实例的操作语义描述方法,这种方法的使用弥补了工作流元模型对测试流程实例描述的不足,并在实际项目中得到了应用,包括过程实例的形式化描述和活动实例的形式化描述,以及状态转移规则的描述,取得了很好的效果。     

MDA框架中CIM业务流模型与PIM工作流模型的一致性验证

对平台无关模型(PIM)层次上的工作流模型进行细化操作，往往会造成计算无关模型(CIM)业务流与PIM工作流不一致的后果。对此，提出业务流模型与工作流模型的一致性验证方法。定义三种不同情形的细化，并利用扩展Petri网形式化描述每种细化的语义条件；设计语义一致性验证步骤；演示语义一致性验证的过程和结果。实验结果表明，该方法可有效地验证PIM工作流模型在细化过程中是否改变了系统的业务流，以及修改的程度。     

Verifying workflow processes: a transformation-based approach

Workflow modeling is a challenging activity and designers are likely to introduce errors, especially in complex industrial processes. Effective process verification is essential at design time because the cost of fixing errors during runtime is substantially higher. However, most user-oriented workflow modeling languages lack formal semantics that hinders such verification. In this paper, we propose a generic approach based on the model transformation to verify workflow processes. The model transformation includes two steps: first, it formalizes the desirable semantics of each modeling element; secondly, it translates a workflow process with clear semantics to an equivalent Petri net. Thus, we can verify the original workflow process using existing Petri net theory and analysis tools. As a comprehensive case study, verifying workflow processes in an industrial modeling language (TiPLM) is presented. Experimental evaluations on verifying real-world business processes validate our approach.     

Modeling and monitoring of E-commerce workflows

Electronic commerce (E-commerce) is an important Internet application that is significantly changing the way of commercial transaction. Due to the complexity of E-commerce systems and lack of well-designed formal models, providing a suitable method for their modeling and monitoring turns out to be a challenging job. This paper introduces labeled workflow nets (LWN) and their semantics on the basis of labeled Petri nets. Then an inter-organizational labeled workflow net (ILWN) - which can graphically model the dynamic behavior of the systems - is presented. Furthermore, the nonblocking property of ILWNs is defined to achieve a common goal of E-commerce participants. This nonblocking property helps to analyze the soundness of ILWNs and the undeniable property of interactive actions. The proposed framework for E-commerce workflows (ECW) can record a history of interactive events and monitor the execution of interactive activities to achieve a common goal. Therefore, it can elegantly model the execution of interorganizational workflows and analyze the accountability of cooperative activities. The main contribution of the paper is to present a new formal mechanism - ILWN. It can efficiently support the modeling and monitoring of ECWs. Finally, this paper illustrates how to use the proposed method by modeling and analyzing a Customer-Producer-Supplier example.     

A Workflow Process Mining Algorithm Based on Synchro-Net

Sometimes historic information about workflow execution is needed to analyze business processes. Process mining aims at extracting information from event logs for capturing a business process in execution. In this paper a process mining algorithm is proposed based on Synchro-Net which is a synchronization-based model of workflow logic and workflow semantics. With this mining algorithm based on the model, problems such as invisible tasks and short-loops can be dealt with at ease. A process mining example is presented to illustrate the algorithm, and the evaluation is also given.     

基于区间代数的工作流模式的建模研究

在业务流程建模阶段,从时态角度采分析业务流程,有助于清楚地描述工作流.在对工作流模式以及其中包含的时态语义进行了深入研究之后,根据区间代数的语法,将工作流模式和区间代数结合起来,提出了一种新的用于工作流模式的时间约束建模方法.它不仅从时态角度扩展了工作流建模,明确描述了工作流模式中和时序有关的时态约束和依赖关系,并且能使工作流控制模式和形式化验证工具结合,从而有利于进一步从时态角度研究业务流程建模.     

Structured design,consistency analysis and failure reasoning of business workflows with activity-control templates and causal ordering

The design, analysis, control and diagnosis of business workflows have been major challenges for enterprise information system designers. We propose a structured framework for workflow design, formal semantics, consistency analysis, execution automation and failure reasoning targeting E-commerce applications. A business workflow is modeled by using a visual tool named activity-control (AC) diagram. Frequently occurring business procedures are captured by the adoptions of reusable AC templates. With formally defined semantics by a combination of first-order logic and happen-before causal ordering in distributed system theory, workflow consistency can be mechanically analyzed at design time while failure reasoning can be applied at execution time for problem diagnosis. A completely specified model is automatically converted to a workflow by an iterative traversal algorithm that maps an AC diagram to an XML workflow specification which can then be executed automatically by an XML workflow engine. A failure reasoning and diagnosis algorithm is devised to find all possible causes of a failed execution when problems occur. Preliminary proof-of-concept implementation and evaluation results demonstrate the feasibility and effectiveness of our framework and techniques.     

支持虚拟企业的过程建模和工作流管理系统

针对虚拟企业提出了一种基于产品开发制造全过程分解和活动描述的形式化过程建模方法,在组成过程的任务中存在许多约束关系,如使能约束和促进约束,每个任务可以分解成许多活动,可以用企业本体论来表示这些活动、任务、状态和约束等,企业本体论是以情景演算来表示语义的,同时,建立了与过程模型相分离的组织模型活动、任务、状态和约束等,企业本体论是以情景演算来表示语义的。同时,建立了与过程模型相分离的组织模型;在此基础上,建立了一个工作流管理系统来支持虚拟的运行。文中提出一种由活动模型、意向模型、技能模型和伙伴模型等构成的Agent模型,来实现工作流管理,并通过构建可嵌套的Agent联帮增强系统的柔性。     

Formalizing the specification and execution of workflows using the event calculus

The event calculus is a logic programming formalism for representing events and their effects especially in database applications. This paper proposes the event calculus as a logic-based methodology for the specification and execution of workflows. It is shown that the control flow graph of a workflow specification can be expressed as a set of logical formulas and the event calculus can be used to specify the role of a workflow manager through a set of rules for the execution dependencies of activities. The proposed framework for a workflow manager maintains a history of events to control the execution of activities. The events are instructions to the workflow manager to coordinate the execution of activities. Based on the already occurred events, the workflow manager triggers new events to schedule new activities in accordance with the control flow graph of the workflow. The net effect is an alternative approach for defining a workflow engine whose operational semantics is naturally integrated with the operational semantics of a deductive database. Within this framework it is possible to model sequential and concurrent activities with or without synchronization. It is also possible to model agent assignment and execution of concurrent workflow instances. The paper, thus, contributes a logical perspective to the task of developing formalization for the workflow management systems.     

一种基于同步网的工作流管理系统

作为一类典型的CSCW系统,工作流管理系统主要提供异步、结构化的协同支持。本文从模型入手,介绍了一种基于Petri网的工作流模型——同步网。它采用分层视图描述了过程逻辑、语义及管理,过程模型和管理模型的互动关系用来指导工作流引擎的构造。本文基于同步网开发了工作流管理系统,支持工作流的定义、执行和管理。为了满足CSCW的需要,工作流管理系统中增加了同步协作机制。     

面向对象的工作流建模工具的设计与实现

在工作流技术和方法的基础上,深入研究了WfMC工作流参考模型、工作流常用建模方法和过程定义语言,采用面向对象的建模方法对工作流进行建模,最后结合实例验证了设计器在处理复杂的工作流过程中具有一定的应用价值,从而为今后工作流的动态执行模型的建立打下了良好的基础.