基于BPEL的流程数据竞争问题研究

服务组合就是将多个基本的Web服务组合成可以满足用户需求的增值服务,为企业或企业间的业务过程集成提供技术支持。作为一种流程驱动的服务组合描述语言,BPEL和其他采用不同方式的服务组合语言一样面临着流程描述的正确性问题,在执行服务组合之前要对其控制流和数据流进行分析和验证。数据竞争是BPEL数据流分析中亟需解决的问题之一。围绕BPEL流程数据竞争问题,在对BPEL规范中的活动类型、活动并发性进行分析基础上,给出了数据竞争的形式化描述,提出一种检测方法。该方法基于XML节点树的特性、活动之间的并发性以及活动关联的消息来判断是否存在潜在的数据竞争。最后,通过一个订单处理流程实例,说明了该方案的有效性。     

Coordinating multiple groups of robots for gaiting process

Coordinated robots are categorized into different groups when the coordination involves robot interchange or heterogeneous motion during the manipulation process. We investigated problems related to the control and coordination of multiple groups of robots and developed a general strategy and control algorithm for controlling one group of robots. We developed a method for determining the force distribution among the participating robots in a frictional equilibrium case. The control algorithm and the force determination procedure can be adopted in coordinating multiple groups of robots. Scenarios and restrictions for coordinating two groups of robots in turning a disk continuously are discussed. An example is given to illustrate the gaiting process. © 1996 John Wiley & Sons, Inc.     

Workflow structuring and reengineering method for design process

A short lead time for product commercialization is a critical advantage in the era of highly challenging competitions. It is more difficult, however, to shorten the design process rather than manufacturing process since the underlying design activities in process and related data are often interlinked and quite uncertain, and the attempts to perform the design activities concurrently increase the complexity of the design process.

In case the targeting process is well-structured and easy to be managed, many approaches have been proposed and it is the best way to use the well-known reengineering method such as crashing the bottle-neck activity. However, they have only concerned mainly about well-defined procedures, not an operational-level sophisticated workflow.

As a means to effectively manage and accelerate the design process, a process or workflow model needs to define complex relations such as iteration or coupled dependency in design process in order to coordinate the sophisticated process effectively. And, the acceleration approaches based on the operational-level information needs to be discussed.

Firstly, in order to develop an appropriate model that effectively captures the operational-level characteristics in design process, we define the workflow including the control and data flow with an incidence matrix called Workflow Matrix (WfM). Secondly, a workflow structuring method is developed for identifying the reengineering issue and it also transform the complex design process into a well-structured workflow. Finally, we analyze the design process with WfM and suggest reengineering strategies to improve the design process.     

多主体业务流程的可靠执行模型

当前工作流管理中,业务流程执行的可靠性是一个不容忽视的重要问题,然而,现有的研究在解决多主体协调并发执行过程中的主体夭折问题存在不足。基于迁移工作流模型,提出一种多迁移实例的可靠执行模型,模型可以实现不同层次上的执行主体监测与故障诊断和处理;同时设计守护实例具有可移动、可复制以及自动退出等特点,有效提高了检测准确性和监控效率。实验表明,模型具有高可靠性和低开销以及可扩展性等技术优势,特别适合当前跨机构环境中多主体的并发执行。     

A linear time layout algorithm for business process models

The layout of a business process model influences how easily it can be understood. Existing layout features in process modeling tools often rely on graph representations, but do not take the specific properties of business process models into account. In this paper, we propose an algorithm that is based on a set of constraints which are specifically identified toward establishing a readable layout of a process model. Our algorithm exploits the structure of the process model and allows the computation of the final layout in linear time. We explain the algorithm, show its detailed run-time complexity, compare it to existing algorithms, and demonstrate in an empirical evaluation the acceptance of the layout generated by the algorithm. The data suggests that the proposed algorithm is well perceived by moderately experienced process modelers, both in terms of its usefulness as well as its ease of use.     

A novel flexible activity refinement approach for improving workflow process flexibility

Flexible activity refinement plays an important role in improving process flexibility and addressing uncertainties of business processes. However, it is still a challenge to refine flexible activities, and the existing researches on flexible activity refinement such as the refinement principles and methods, and their combination with factors such as constraints and contexts is still lacking. Aiming at this, a novel dynamic refinement approach for flexible activities is proposed, which combines both vertical decomposition and horizontal extension refinements, with the impact of constraints and contexts considered. In particular, we summarize five typical refinement categories, and present a set of activity refinement rules based on them. Furthermore, the decomposition refinement, including the activity decomposition principles, the related rules for trigger event delivering and execution condition transferring is discussed in detail. The extension refinement, which realizes the horizontal refinement, can be integrated with other kinds of refinement and uses constraints to specify activity selection, activity temporal relationships, etc. Then, a tree-like activity refinement graph (ARG) is proposed to represent the refinement process, based on which the refinement cost and refinement degree can be computed to benefit the finding of the potential optimal refinement path. As a further implementation of the proposed refinement approach, a general refinement algorithm is described. Finally, a case study of urolithiasis therapy process and its application are given, and the results indicate the effectiveness of our proposals.     

A secure migration process for mobile agents

This article describes a decentralized secure migration process of mobile agents between Mobile‐C agencies. Mobile‐C is an IEEE Foundation for Intelligent Physical Agents (FIPA) standard compliant multi‐agent platform for supporting C/C++ mobile and stationary agents. Mobile‐C is specially designed for mechatronic and factory automation systems where malicious agents may cause physical damage to machinery and personnel. As a mobile agent migrates from one agency to another in an open network, the security concern of mobile agent systems should not be neglected. Security breaches can be minimized considerably if an agency only accepts mobile agents from agencies known and trusted by the system administrator. In Mobile‐C, a strong authentication process is used by sender and receiver agencies to authenticate each other before agent migration. The security framework also aims to guarantee the integrity and confidentiality of the mobile agent while it is in transit. This assures that all agents within an agency framework were introduced to that framework under the supervision and permission of a trusted administrator. The Mobile‐C Security protocol is inspired from the Secure Shell (SSH) protocol, which avoids a single point of failure since it does not rely on a singular remote third party for the security process. In this protocol, both agencies must authenticate each other using public key authentication, before a secure migration process. After successful authentication, an encrypted mobile agent is transferred and its integrity is verified by the receiver agency. This article describes the Mobile‐C secure migration process and presents a comparison study with the SSH protocol. The performance analysis of the secure migration process is performed by comparing the turnaround time of mobile agent with and without security options in a homogeneous environment. Copyright © 2010 John Wiley & Sons, Ltd.     

BPEL4WS协议中数据共享问题的研究

针对BPEL4WS协议在流程执行中数据共享问题处理上的不足,对协议的内容进行了拓展,提出“容器池”概念,假设了它的构建模型。在实际例子中进行应用和分析,分别探讨了在同一流程下数据共享和不同流程下数据共享的两种应用情形。     

Coordinating Mobile Agents by the XML-Based Tuple Space

This paper presents Xspace,a programmable coordination paradigm for Internet applications based on mobile agents.The Xspace system fully exploits the advantages of the XML language and Linda-like coordination.It supports XML documents as tuple fields and multiple matching routines implementing different relations among XML documents,including those given by XML query languages,The Xspace uses Java as the implementation language;it is based on object-oriented XMLized tuple spaces to implement a portable and programmable coordination paradigm for mobile agents.The dsign and implementation procedures of Xspace are described in this paper,Experiment and performance evaluation are also made.Finally,some conclusinos and remarks are given.     

Execution system for distributed business processes in a virtual enterprise

New cooperative approaches for manufacturing and service industries, as represented by the virtual enterprise paradigm, are enabled by the recent advances in communication technologies, computer networks, and logistics. The implantation of this paradigm requires the design and development of a flexible execution environment to support the distributed business processes that materialize the cooperation in a network of enterprises. A configurable architecture for such execution system is proposed focusing the support for multi-level process coordination. A set of examples to illustrate the adopted concepts and developed tools are discussed.     

分离业务规则和过程流的业务过程模型研究

针对动态环境中业务逻辑的不断变化,通过业务规则和过程流分别描述业务过程中的易变和相对稳定业务逻辑,构建了业务过程模型BPM4DBL（Business Process Model for Dynamic Business Logic）。模型引入了活动、规则和事件元素,定义了分离业务规则和过程流的元组表达,并且给出了业务规则和过程流之间的耦合策略。最后,给出了一个BPM4DBL的具体应用实例。     

A decentralized execution model for inter-organizational workflows

Workflow Management Systems (WFMS) are often used to support the automated execution of business processes. In today’s networked environment, it is not uncommon for organizations representing different business partners to collaborate for providing value-added services and products. As such, workflows representing the business processes in this loosely-coupled, dynamic and ad hoc coalition environment tend to span across the organizational boundaries. As a result, it is not viable to employ a single centralized WFMS to control the execution of the inter-organizational workflow due to limited scalability, availability and performance. To this end, in this paper, we present a decentralized workflow model, where inter-task dependencies are enforced without requiring to have a centralized WFMS. In our model, a workflow is divided into partitions called self-describing workflows, and handled by a light weight workflow management component, called the workflow stub, located at each organization. We present a performance study by considering different types of workflows with varying degrees of parallelism. Our performance results indicate that decentralized workflow management indeed enjoys significant gain in performance over its centralized counterpart in cases where there is less parallelism. The work of V. Atluri is supported in part by the National Science Foundation under grant IIS-0306838.     

层次化服务流程向可执行BPEL转换的方法

基于人工智能规划的服务组合算法得到的组合方案是一种层次化服务流程（layered service process, LSP）,由服务之间的数据流（而非传统块结构流程中的控制结构）加以驱动执行。为使该类服务流程能在业务
　　过程执行语言（business process execution language,BPEL）引擎上直接执行,研究了将LSP转换为BPEL的方法,追求BPEL执行效率的优化。给出了LSP的形式化模型,分析了将LSP转换为BPEL的3种策略（完全拆分、按层拆分、按块拆分）,定性对比了三者之间的性能优劣。针对按块拆分策略,提出了9条规则用于对LSP的拆分,提出了块拆分算法和块合并算法。通过一个LSP案例对转换过程进行了演示,并通过实验证实了该转换方法可以获得比其他转换策略性能更好的BPEL。     

A conceptual framework for understanding business processes and business process modelling

It is increasingly common to describe organizations as sets of business processes that can be analysed and improved by approaches such as business process modelling. Successful business process modelling relies on an adequate view of the nature of business processes, but there is a surprising divergence of opinion about the nature of these processes. This paper proposes a conceptual framework to organize different views of business processes under four headings. It also aims at providing an integrated discussion of the different streams of thought, their strengths and limitations, within business process modelling. It argues that the multifaceted nature of business processes calls for pluralistic and multidisciplinary modelling approaches.     

面向业务人员的动态业务过程改变方法

针对目前业务过程修改和实例迁移系统对使用者的技术背景要求较高的问题,提出了一个面向业务人员的动态业务过程改变方法,进行了一致性分析,并给出了业务过程设计器。业务过程设计器基于业务过程模型和符号2.0规范。该规范易于业务分析人员掌握及建模,并具有可执行语义。针对由于业务过程重组导致的业务过程改变的常见模式,提出了业务过程改变操作类型。业务过程设计器支持业务过程改变操作类型,将IT人员解放出来,降低了业务人员与IT人员交流的成本。     

工作流管理原型系统的设计与实现

对工作流管理原型系统的实现方式进行研究是具有现实意义的工作。工作流在规范企业业务流程的同时还可以完成业务流程的重组，从而更适应于当今企业管理信息系统的要求和特点。本文所设计的工作流管理系统虽然只是一个原型系统，但这种原型系统不仅可以简化开发过程的复杂性，而且还可以突出整个系统所必须的主要部分。实现后的原型系统，可以方便地进行扩展，将更多复杂的引擎功能加入到系统中，实现该工作流管理系统的逐步完善并将工作流技术引入到企业管理信息系统的开发中去。     

A systematic approach to business process reengineering

In this study, a business process is defined as a set of various tasks which are closely inter-related and is assumed to have its own objectives to achieve. A set of processes constitute a business system. Many business process reengineering plans turned out to be unsuccessful because they are based on the existing process which assumed tasks along the process independent or based on the assumption that a process is independent of other processes. This approach generated redundant tasks or led to conflict between business processes. Under this approach, it very difficult to predict the result of the plan due to localized analysis of the process. To avoid aforementioned problems, a systematic, analytic and iterative approach to build up a master plan for business process reengineering is proposed.     

面向跨组织业务流程的角色行为验证方法

为了更有效地保证跨组织业务流程模型的正确性和合理性,应用Pi演算提出了一种基于状态的角色行为的验证方法。基于Pi演算提出了跨组织业务协作中的角色模型,设计了角色描述表,以清晰、直观地描述角色的权利、职责和义务,进而应用Pi演算验证工具MWB(移动工作平台)的check和step命令提出了单角色验证方法,并在此基础上从业务对象状态和业务操作角度提出了多角色验证方法。实现了角色行为的验证,并为跨组织业务流程的可达性、一致性和死锁等分析奠定基础。     

An OWL-based semantic business process monitoring framework

Process monitoring phase is one of the service-oriented business process (SOBP) lifecycle phases. Traditional process monitoring approaches have been only achieved at the syntactic level of the process monitoring contexts, which causes the communication problems such as ambiguous understandings and divergent interpretations. To solve the problems, the process monitoring should be achieved at the semantic level as well as at the syntax level of the process monitoring context. In order to support semantic monitoring operations, an ontology-based monitoring framework for the SOBP execution is suggested in this paper. The suggested framework combines a BPEL4WS process model with the semantic monitoring context which is expressed with OWL.