Adaptive integration activity management for on demand business process collaboration

Today businesses are interacting and collaborating more often in the context of a business value chain involving a variety of partners to deliver products and services. Business to business (B2B) connectivity, Enterprise Application Integration (EAI) and general business collaboration processes are becoming more critical in operating and managing efficient enterprises. The required level of inter and intra enterprise integration is generally a large undertaking and involves substantial development and customization efforts. In this paper, we propose an adaptive integration activity management approach based on web services technologies to reduce code changes associated with business process integration in a distributed collaboration environment. Specifically, we present a concept of activity chain to capture non-deterministic process flows as well as deterministic process flows in a uniform manner. Then an Activity Ontology is introduced to capture the integration requirements that include adaptation behaviors, action properties, business rules, and access control policy references. The unique ontology representation and management of the integration activities provides a uniform way to integrate additional internal and external business applications to reduce the need for pre-defined and hard-wired integration methods and to minimize code changes to existing components in an existing business collaboration and integration (B2B/EAI) infrastructure. In addition, a Petri-Net modeling exercise of the proposed integration activity management is performed to help better understand the actual system and improve the system design beforehand.     

An experience report on developing an automated web services platform

Web services have attracted significant industry interest as a low-cost and flexible technology alternative to distributed object and proprietary message-oriented methods for delivery of on-demand business processes, enabling intra-organizational systems integration, and in the long term, development of dynamic inter-organizational process networks that may revolutionize B2C and B2B e-commerce. Exploiting this latent potential of web services technology requires the development of automated techniques for scalable and reliable service composition and execution in web service platforms. In this paper, we summarize our experience in developing an architectural framework for web services platforms, called Integrated Service Planning and Execution architecture (ISP & E). The use of recent advances in AI planning, learning and semantic web technologies for service composition, reliable service execution, transaction synthesis, and model-driven deployment of services is discussed. Furthermore, we discuss implications for and research issues in the development of web services based systems to aid e-business.     

Interacting services: From specification to execution

Interacting services play a key role to realize business process integration among different business partners by means of electronic message exchange. In order to provide seamless integration of these services, the messages exchanged as well as their dependencies must be well-defined. Service choreographies are a means to describe the allowed conversations. This article presents a requirements framework for service choreography languages, along which existing choreography languages are assessed. The requirements framework provides the basis for introducing the language BPEL4Chor, which extends the industry standard WS-BPEL with choreography-specific concepts. A validation is provided and integration with executable service orchestrations is discussed.     

Synthy: A system for end to end composition of web services

The demand for quickly delivering new applications is increasingly becoming a business imperative today. However, application development is often done in an ad hoc manner resulting in poor reuse of software assets and longer time-to-delivery. Web services have received much interest due to their potential in facilitating seamless business-to-business or enterprise application integration. A web service composition system can help automate the process, from specifying business process functionalities, to developing executable workflows that capture non-functional (e.g. Quality of Service (QoS)) requirements, to deploying them on a runtime infrastructure. Intuitively, web services can be viewed as software components and the process of web service composition similar to software synthesis. In addition, service composition needs to address the build-time and runtime issues of the integrated application, thereby making it a more challenging and practical problem than software synthesis. However, current solutions based on business web services (using WSDL, BPEL, SOAP, etc.) or semantic web services (using ontologies, goal-directed reasoning, etc.) are both piecemeal and insufficient. We formulate the web service composition problem and describe the first integrated system for composing web services end to end, i.e., from specification to deployment. The proposed solution is based on a novel two-staged composition approach that addresses the information modeling aspects of web services, provides support for contextual information while composing services, employs efficient decoupling of functional and non-functional requirements, and leads to improved scalability and failure handling. We also present Synthy, a prototype of the service composition system, and demonstrate its effectiveness with the help of an application scenario from the telecom domain.     

基于语义的业务流程一致性评价

随着Internet技术的不断发展,电子商务中的B2B应用也逐渐成为企业之间进行业务活动的主要依托技术,企业定义了自己的业务流程,双方业务流程的一致性在业务伙伴间的协作中扮演着非常重要的角色。目前,已经有诸如BPEL4WS和ebXML这样的电子商务技术能够使得企业在业务流程级进行协作,但这些技术均是基于XML技术,所提供的功能主要是语法上的,很少涉及他们的业务流程的一致性评价。为此,扩展了ebXML框架以支持业务流程的一致性评价,设计了一个一致性评价代理来执行客户企业的需要,并搜寻ebXML注册中心的潜在伙伴的业务信息,基于良好定义的一致性标准测试他们与客户企业业务流程间的一致性,最后提交一个评价结果给客户企业。通过这样的过程,客户企业能够找到合适的业务伙伴。而且,采用了语义网的方法,使得评价的结果更加准确。     

Coordinating multiple agents for workflow-oriented process orchestration

Distributed component-based services and semantic web services are promising technologies for next generation inter-enterprise integration. The dynamic nature of this domain presents a complex problem for tools that intend to support this cross-organizational integration. However, the autonomy and adaptation of software agents represent a viable solution for the composition and enactment of cross-organizational services. Currently, there are few studies that measure the impact of the dynamic environmental effects on service composition. On an on-going basis, composite services or workflow processes of web services may be constantly changing in terms of responsiveness of services, accessibility of services and their meta-information, business process schema changes, etc. These conditions impact what interactions a team of agents must undergo to achieve a specific process derived of composite web services. This paper describes an approach, model, and supporting software toward the efficient design of interaction protocols for coordinating agent teams in the business process orchestration domain. This approach considers several environmental conditions related to the dynamism of the Internet.     

The semantics and verification of timed service choreography

As a service composition and coordination language, the service choreography gives the global and neutral view on the collaboration among a collection of highly distributed services involving multiple different organizations or heterogeneous independent processes. In this paper, we extend the service choreography by introducing the explicit time activity, which can be used to specify and reason about the timed behaviour of Web service choreography. Then we explore an execution model for the proposed timed service choreography which possesses several novel features, such as timed activity, choreography composition, exception handling and finalization. Furthermore, a set of mapping rules is elaborately designed to translate the timed choreography into communicating sequential programs processes, thus the corresponding simulation and verification of Web services choreographies with timing restrictions can be carried out in the model checker process analysis toolkit. The case study shows that our approach is both effective and practical.     

Web服务组合行为一致性的形式化描述和分析

Web服务编排和Web服务编制从全局和局部分别定义了Web服务组合的全局交互行为和每个参与者的局部行为,为了保证Web服务组合实现的正确性,Web服务组合的全局交互行为和每个参与者的局部行为必须是一致的。首先利用进程代数给出了对Web服务组合的全局交互行为、局部行为以及二者之间的映射关系的形式化描述,在此基础上分别通过分析全局会话变迁和局部进程变迁的关系和进程互相似理论给出了Web服务组合全局交互行为和局部行为的一致性的两个形式化判定准则。同时通过案例说明了如何形式化地检测Web服务组合的全局交互行为和局部行为之间的一致性。结果显示提出的Web服务组合一致性形式化定义和检测方法能检测组合行为的一致性,从而能有效地保证Web服务组合的正确性。     

服务时间随机条件下服务组合质量分析

本文分析采用业务过程执行语言（BPEL2WS）描述的web服务组合的执行时间,给出在服务执行时间随机情况下,根据单个服务的执行时间概率分布密度和BPEL2WS模型的结构求解web服务组合执行时间的概率分布密度函数的算法。根据概率密度函数可以求得业务过程执行时间在任意时限内的概率,从而可以根据给定的概率条件优化组合服务,使得服务执行成本最低．最后通过一个应用实例验证了算法的有效性。     

Specifying and verifying contract-driven service compositions using commitments and model checking

The paper proposes a novel model checking-based approach towards verifying the compliance of intelligent agent-based web services with contracts regulating their compositions specified in the Business Process Execution Language (BPEL). Unlike the existing approaches in the literature, the main contribution and impact of the introduced approach is the ability to verify intelligent and autonomous composite web services by capturing and describing in details both compliance and violation behaviors, how the system can distinguish between them, and how the system reacts and can be recovered after each violation. The approach encompasses three contributing parts, namely: 1) the marking process of an extended BPEL; 2) the transformation of the extended and marked BPEL to an automata model; and 3) the encoding of the resulting automata model into the Interpreted Systems Programming Language (ISPL), the input language of the MCMAS model checker for intelligent and autonomous multi-agent systems. In the first part, we extend BPEL that specifies the business process of the composition by creating custom activities called labels. We use those labels as means to represent the specifications and mark the points the developer aims to verify. A significant advantage of this labeling is the ability to highlight specific points in the design to be verified and to distinguish compliance behaviors from violations, which makes this verification focused and highly efficient. In the second part, we introduce new transformation rules to transform the extended and marked BPEL to an automata model. This transformation requires a prior modeling of agent-based web services composition using automata definitions. In the third part, we introduce algorithmic translation rules encoding the resulting automata model into ISPL. This translation makes model checking the behavior of our contract-driven compositions possible. A novel characteristic of the proposed approach is the automatic generation of the properties against which the system is verified from the composition’s implementation, which is technically challenging. The verification properties are expressed in the Computation Tree Logic of Commitments (CTLC). Technically, CTLC provides a powerful representation to formally model 1) interactions among multi-agent based web services and 2) compliance and violation behaviors within composite business contracts by making use of communicative commitment operators. CTLC also includes a fulfillment operator which helps formally check the compliance with business contracts and specify the system recovery. A detailed case study from expert and intelligent systems domain along with experimental results are also reported in the paper. Finally, the main impact and significance of the paper on expert and intelligent systems is the ability to use these systems safely since there is a way to verify if the intelligent components behave according to and in compliance with the underlying regulating contracts.     

基于颜色Petri网的服务组合建模与验证

Web服务组合技术能快速、灵活的满足复杂多变的业务需求,Web服务组合及其形式化描述和验证已经成为Web服务中一个非常重要的研究方向.给出了一个基于颜色Petri网(CPN)的Web服务和Web服务组合的形式化定义和描述,主要描述了4种组合结构:顺序、选择、并发和循环.给出了一个颜色Petri网建模Web服务组合的实例,并且对模型进行了简单的正确性分析.分析结果表明,该建模方法满足正确性要求.     

Web服务核心支撑技术:研究综述

随着电子商务的迅速崛起,基于Web的应用模式迅速发展,Web应用从局部化发展到全球化,从B2C(business-to-customer)发展到B2B(business-to-business),从集中式发展到分布式,Web服务成为电子商务的有效解决方案.Web服务是一个崭新的分布式计算模型,是Web上数据和信息集成的有效机制.Web服务的新型构架,Web服务的高效执行方式,Web服务与其他成熟技术的有机结合以及Web服务的集成是解决现实应用问题的重要技术.从Web服务研究的不同侧面对其进行了综述,阐述了Web服务的基本概念,分析了当前Web服务的主要研究问题及其核心支撑技术,概括了Web服务中的数据集成技术、Web服务的组合、语义Web服务、Web服务发现,Web服务安全,P2P(Peer-to-Peer)新型计算环境下的Web服务解决方案和网格服务等方面的研究内容,并对这些技术进行了总结,结合已有的研究成果,展望了Web服务未来的研究方向及其面临的挑战.     

Standards-based approaches to B2B workflow integration

E-business automates the overall activities of a company and allows distributed systems to communicate their information. Process automation and information sharing improve a company’s productivity and responsiveness, while Business-to-Business (B2B) workflow systems electronically aid the progress of business processes among trading partners, and also help companies to monitor and administrate their process execution. This study analyzes the technologies and standards for B2B workflow integration, and extracts a reference model for B2B workflow integration. Based on the reference model, three approaches to B2B workflow integration will be introduced here. In addition, we have developed a prototype system of one approach and have illustrated an example for B2B workflow integration. The result of our research can help business partners understand the workflow standards and the messaging technologies for B2B workflow integration, and also help them understand how to implement workflow integration systems that are appropriate to their e-business environments.     

基于服务网格的制造资源集成

提出了一种基于服务网格的制造资源集成方法，通过将服务网格技术引入制造行业，实现了制造资源的虚拟化，为制造资源提供了统一的接口和互操作协议、屏蔽平台及所使用技术的异构性。平台采用基于服务的协同工作流技术，在动态变化的环境中，能够根据用户需求优化业务逻辑及其执行过程，选择、配置和调度相应的制造资源完成指定的任务，实现跨组织的资源共享和任务协同。     

基于Web服务的动态工作流系统的研究与实现

分析了面向服务的计算环境及服务组合的新特征和新问题,并在此基础上从面向业务用户的角度对基于Web服务的动态工作流进行了探讨,提出一种基于Web服务的动态工作流模型。以该模型为基础,设计了具有三层结构的基于Web服务的动态工作流系统,按照该架构并基于J2EE平台实现了系统,对基于Web服务的动态工作流应用提供了系统支撑与验证环境。     

Research on dynamic business composition based on web service proxies

Web services-based business composition brings a number of advantages to the enterprise application development. How to select and compose the web services based on their functionality and QoS (Quality of Service) dynamically prove to be more and more important. In this paper we develop a proxy-based framework to compose Web services dynamically. The framework is featured with a QoS model, an effective service discovery and selection algorithms to facilitate the dynamic integration of Web services and management of abnormalities. Furthermore, a business process constructing method based on service slice is put forward to satisfy the users’ personalized requirements more effectively and flexibly. Our study concerns both functionality and QoS characteristics of Web services to identify the optimal business process solutions. A Complete case study is also included in this paper and the performance demonstrated that the framework and algorithms can provide a tangible and reliable solution to dynamic Web service composition and adaptation.     

基于Web服务的动态工作流系统的研究与实现

分析了面向服务的计算环境及服务组合的新特征和新问题，并在此基础上从面向业务用户的角度对基于Web服务的动态工作流进行了探讨，提出一种基于Web服务的动态工作流模型。以该模型为基础，设计了具有三层结构的基于Web服务的动态工作流系统，按照该架构并基于J2EE平台实现了系统．对基于web服务的动态工作流应用提供了系统支撑与验证环境。     

Meta web service: building web-based open decision support system based on web services

Web services are currently one of the trends in network-based business services, which intuitively will be applied to build a semantic web-based decision support system (DSS). Since web services are self-contained, modular business process applications, based on open standards, enable integration models for facilitating program-to-program interactions. Decision modules in a semantic web-based DSS can be viewed as a web service. However, according to the current features, web services know only about themselves, they are neither autonomous, nor are they designed to use ontologies; they are passive until invoked, and they do not provide for composing functionalities. These lead to the motivation on building a sophisticated web service to contain these features and to utilize web services on behalf of the user. This paper aims to propose a new concept of Meta Web Service, a web service-based DSS. The meta web service understands the user's problem statement with ontology, performs web service discovery, web service composition, and automatically generates codes for composite web service execution. Case-based reasoning is applied to quickly find past histories of successful service compositions. A prototype of research web service has been developed to show the feasibility of the proposed idea.