Web Services Workflows—Composition, Co-Ordination, and Transactions in Service-Oriented Computing

Web services can be seen as a newly emerging research area for Service-oriented Computing and their implementation in Service-oriented Architectures. Web services are self-contained, self-describing modular applications or components providing services. Web services may be dynamically aggregated, composed, and enacted as Web services Workflows. This requires frameworks and interaction protocols for their co-ordination and transaction support. In a Service-oriented Computing setting, transactions are more complex, involve multiple parties (roles), span many organizations, and may be long-running, consisting of a highly decentralized service partner and performed by autonomous entities. A Service-oriented Transaction Model has to provide comprehensive support for long-running propositions including negotiations, conversations, commitments, contracts, tracking, payments, and exception handling. Current transaction models and mechanisms including their protocols and primitives do not sufficiently cater for quality-aware and long running transactions comprising loosely-coupled (federated) service partners and resources. Web services transactions require co-ordination behavior provided by a traditional transaction mechanism to control the operations and outcome of an application. Furthermore, Web services transactions require the capability to handle the co-ordination of processing outcomes or results from multiple services in a more flexible manner. This requires more relaxed forms of transactions—those that do not strictly have to abide by the ACID properties—such as loosely-coupled collaboration and workflows. Furthermore, there is a need to group Web services into applications that require some form of correlation, but do not necessarily require transactional behavior. The purpose of this paper is to provide a state-of-the-art review and overview of some proposed standards surrounding Web services composition, co-ordination, and transaction. In particular the Business Process Execution Language for Web services (BPEL4WS), its co-ordination, and transaction frameworks (WS-Co-ordination and WS-Transaction) are discussed.

基于模拟的企业过程模型自动优化技术研究

企业过程模型参数自动优化是一个多参数多目标的系统优化问题.采用线性加权法将其转换成多参数单目标问题的求解,提出基于计算机模拟的企业过程模型参数的自动寻优方法.它将传统的共轭梯度法FR（fletcher reeves）和禁忌搜索算法TS（tabu search）结合起来,采用FR法进行局部寻优,由TS法实现从当前局部最优点向全域范围内的更优区域转移,循环往复达到求出全域范围最优点的目的.改进了FR法与TS法,克服了各自的缺陷,并提出禁忌区域表的概念,从而加速寻优过程.它适用于任意多维曲面的多极值问题最优求解,对企业进行BPR（business process reengineering）和实施ERP（enterprise resource planning）管理有较大的指导意义.

BPMN与BPEL双向转换系统的设计与实现及其应用

随着SOA和业务流程管理BPM技术日益成熟，基于业务流程的开发得到越来越广泛的应用。BPMN是由国际标准组织BPMI所制定的业务流程描述语言，制定了标准化的图形符号用于流程的设计和交流。WS-BPEL是面向服务计算中服务复合层重要的技术规范，WS-BPEL支持通过组合分布异构的服务形成复杂的业务流程。BPMN和BPEL模型之间存在差异，跨越两者之间的鸿沟实现无缝转换是当前服务计算中的关键问题之一。现有的BPMN到BPEL转换方法对用户建模限制太大，并且转换后的BPEL不能直接部署和运行，自动化程度不高。现有BPEL到BPMN转换方法缺少对复杂BPEL结构的转换。 针对这些问题，论文设计了一套双向模型转换方法。首先分析了现有BPMN到BPEL的转换方法。然后根据分析结果对已有的BPMN到BPEL转换方法进行扩展，并着重解决了路由OR和并发多实例Multi-instance的语义分析和转换这一难点问题，减少了用户建模时的限制，转换得到的可直接执行的BPEL，提高了自动化程度。在此基础上，设计了BPEL到BPMN的转换方法，采取自上而下的扁平化策略来将嵌套块结构的BPEL控制流转换成为平整无层次的流程图结构，其中分析了Link设置不同条件时的语义并分别转换到对应的BPMN结构，解决了复杂BPEL结构的转换。 最后，我们在流程设计平台OnceBPD（Once Business Process Designer）实现了双向转换功能，能够将BPMN模型转换为BPEL模型，得到的BPEL文件可以部署和运行在OnceBPEL流程执行引擎。还可以将BPEL模型装换为BPMN模型，并应用于OnceBPEL引擎监控信息的可视化，实现了在OnceBPD中直观、形象的显示流程监控。

事件驱动的BPEL引擎架构设计与实现

WS-BPEL(Web Service Business Process Execution Language，简称BPEL)是Web服务规范族中服务复合层的重要标准。BPEL支持通过对Web服务的编制(Orchestration)来构建业务流程，从而使编程人员能够集中关注业务逻辑。BPEL引擎系统是一个支持BPEL语言描述的业务流程运行的服务器中间件系统，使用BPEL引擎可以执行BPEL语言编写的业务流程。作为一个网络服务器系统，BPEL引擎将不可避免的处理大量的并发请求。如何设计实现BPEL引擎使之能高效的处理并发将是高性能BPEL引擎设计的关键问题。 并发服务器系统通常采用多线程和事件驱动两种并发模型。传统上大多数服务器软件都建立在多线程(或多进程)模型的基础上。但在高负载条件下，过多的线程和线程间的上下文切换会造成系统较大的开销，这些开销是导致系统性能下降的主要原因。事件驱动模型是一种只采用少量固定数量线程的并发模型，一般说来，它的伸缩性更好，并且有更高的处理效率。 本文对高并发服务器系统中所使用的事件驱动模型进行了分析和研究，并且结合BPEL语言规范的特点，提出了事件驱动的BPEL引擎实现技术方案。论文重点研究了BPEL事件结构和有限状态机(Finite State Machine，简称FSM)刻画BPEL流程和活动行为的原理，针对BPEL语言语法特点，构造了完整的BPEL FSM模型，包括了状态空间和基于ECA(Event-Condition-Action)模式的状态转移规则。 在基于事件驱动模型的BPEL引擎架构原理的指导下，我们设计并实现了基于事件驱动模型的OnceBPEL2.0引擎系统。并且，我们对采用多线程模型实现的OnceBPEL1.0系统和采用事件驱动模型实现的OnceBPEL2.0系统进行了性能测试和分析比较。从我们的测试数据和分析结果可以看出，采用事件驱动模型的OnceBPEL2.0系统比采用多线程模型的OnceBPEL1.0有了较大的性能提升。

BPEL流程监视的可视化实现

When a BPEL process is executed,it is necessary to dynamically monitor the process.BPEL is a executable language,which is not suitable for visual monitoring.On the other hand,BPMN is designed to visually describe business process and is more intuitive for monitoring.To visually monitor a BPEL process, transformation from BPEL to BPMN is necessary.However,current study of transformation from BPEL to BPMN does not support the transformation of"link"activity.Besides,no work has been done to add supplementary information into BPMN during transformation.In this paper,we transform nested BPEL process into a flat BPMN process graph without hierarchy through applying a flattening strategy.Especially, we analyze various scenarios of the transformation of link activity,and provide a method to deal with it. Besides,we analyze the mapping between BPEL activities and BPMN graph,through which we found out that some supplementary information cannot automatically obtained from BPEL process.These supplementary information need to be added during transformation.At the end of this paper,we present the structure of our monitoring tool which is based on our transformation algorithm.

企业经营系统的对象模型──资金流模型

本文阐述了大型工业企业综合自动化系统体系结构中经营管理层的对象模型（资金流模型）。首先论述了该模型在自动化体系结构中的地位和作用，然后分析了企业生产经营过程中发生的资金流，提出用借贷流程图方法表达资金流模型，并将这一方法与国际通用的借贷记帐法相联系，从而揭示了资金流模型与会计核算的内在联系．本文还对企业生产与经营活动的几个主要过程用借贷流程图进行了细化描述。

基于RFID的混流装配汽车生产线物料动态配送研究

针对混流装配的汽车自动化生产线提出了基于RFID的车辆追踪和基于条码的无线物料库存管理实现方法。在此基础上,设计了装配生产线的物料动态配送调度业务流程,给出了物料动态配送的规划依据,并进行了实例计算。

bridge the gap between software test process and business value: a case study

Chinese Academy of Sciences (ISCAS)