一种支持过程动态更新的过程系统设计与实现

在当前开放、变化的Internet环境下,业务过程需要在运行时进行动态更新,同时将原过程下正在运行的实例迁移到更新后的过程模型下.设计了一种支持动态更新的过程系统.在模型层面上,使用AOP(Aspect Orient Programming,面向方面编织)的方法,实现流程运行时动态更新生成新的模型.在引擎层面上,修改原有引擎,使其能够暂停、恢复实例的运行,从而支持实例的动态迁移.在实例层面上,提出了一种实例迁移的算法,为模型提供动态更新的能力.最后,介绍一个应用案例以验证系统的正确性.     

基于Petri网模型的工作流实例迁移算法

工作流实例迁移是工作流演化研究中的一个重要问题.目前,大部分的工作流实例迁移策略是基于版本控制的,工作流实例不能及时迁移到新模型中运行.分析了工作流实例迁移过程中所存在的动态变更错误,并结合自由选择网的经典理论,提出了一种基于Petri网模型的工作流实例迁移算法.根据工作流实例迁移后的状态可达性,来确定该实例能否正确迁移,算法的时间复杂度是多项式的.     

一种支持工作流动态修改并自动迁移的方法

工作流技术中一个重要而开放的问题就是工作流的演进问题（evolution of workflow Schemas）,即创建、删除、修改工作流过程并使整个模型保持正确.被修改工作流过程的实例必须尽量与新的工作流过程保持一致.本文提出了一种支持工作流动态修改并完成实例自动迁移的工作流模型,并在此基础上定义了一系列修改操作原语及动态迁移策略语言.根据修改操作原语所涉及的任务节点的偏序关系生成变化区域,再根据变化区域自动生成相应的迁移策略,这样各工作流实例就可以按照迁移策略自动地实现迁移.     

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。     

Web服务组合动态演化的实例可迁移性

组合网络上既有Web服务以构造新的增值服务正逐渐成为一种主流软件形态.而Web服务组合常需进行修改演化以优化服务组合的内部业务流程,适应开放的工作环境.在服务组合演化时,为让尽可能多的执行中的服务组合实例享受到新业务流程带来的好处,应尽可能地将其动态地迁移到新流程下继续执行.同时为避免实例迁移到新流程后引发死锁等动态演化错误,需对这些迁移实例加以约束.文中提出了一个服务组合动态演化过程框架,在此框架下形式化地定义了一种新的实例可迁移性标准,并给出了相应的判定算法.与已有的可迁移性标准相比,该标准在确保不会产生动态演化错误的同时,可允许更多的实例迁移.最后,通过一个旅行代理的服务组合案例,说明了文中工作的有效性和可行性.     

一种基于目标的过程实例演化方法

过程具有长生命周期、分布式结构、异构等特性.为适应不可预料的环境变化,过程还需要不断地演化.提出一种过程实例的演化方法以控制对过程实例的改变.它可以检查并保证演化前后的过程实例具备"基于目标的行为一致性",从而避免用户对过程的盲目修改.目标作为行为一致的标准,需要分析演化后的过程实例来保证它可以完成目标.通过用Büchi自动机描述过程实例和其目标的语义,一个过程实例是否能够完成其目标是可判定的.     

一种基于反射的BPEL业务过程动态演化方法*

提出了一种基于反射的BPEL业务过程动态演化方法.该方法基于可反射的BPEL业务过程的动态演化框架,扩展了现有BPEL引擎,并对演化元过程建模,使其在BPEL引擎中实例化执行,来实现对业务过程的动态演化.     

基于过程结构树的过程模型变体匹配技术

随着过程模型的不断积累和演化,企业组织常常拥有并管理维护成百上千个业务过程模型.由于建模目标和应用场景的不同,参考模型的裁剪和定制以及模型的更新修改等因素,导致过程模型库中可能存在大量相似的过程模型变体.重点研究如何有效管理和识别过程变体之间的共同点和差异性,即自动化地构建过程模型变体之间的匹配关系.为了支持复杂对应关系,保证匹配关系查找效率和结果的有效性,提出了基于过程结构树的模型元素匹配关系构建技术,并进一步给出了基于树编辑距离的过程模型相似性度量方法.通过针对真实的过程模型集合的实验评估表明,该方法在查全率和查准率指标上表现出了良好的效果.     

多学科协同设计模型感知研究*

为了解决多学科异构系统中产品设计模型之间设计修改的感知问题, 针对设计模型和分析模型提出由模型寻找到协同适应的模型感知应用方法,阐述了各学科之间协同感知过程、感知之后映射关系更新和分析模型修改的实现流程,将传统的人与人感知模式转变为模型到模型感知模式。通过分析模型修改方法实现设计模型到分析模型的感知处理,重新处理分析模型。最后通过感知表达方法实现分析模型到设计模型的感知表达,将分析结果可视化反映到设计模型上。     

SAP平台上统一生产过程的实现

通过一个项目的实例, 本文论述了在SAP平台上实现统一的生产过程,并给出了解决方案.集团下属公司在各自的SAP系统中,定义了自己的生产过程.当迁移到同一SAP平台上时,要求统一的生产过程.     

Time patterns for process-aware information systems

Companies increasingly adopt process-aware information systems (PAISs) due to their promising perspectives for improved business process support. Although the proper handling of temporal constraints is crucial in this context, existing PAISs vary significantly regarding their support of the temporal perspective of a business process. To make PAISs comparable with respect to their ability to deal with temporal constraints and to facilitate the development of a time-aware PAIS, this paper suggests 10 time patterns. All patterns are based on empirical evidence we gathered in case studies. Additionally, they are validated through a systematic literature review. Based on the time patterns, we then provide an in-depth evaluation of selected PAISs and academic approaches. Altogether, the 10 time patterns will not only facilitate the selection of technologies for realizing time- and process-aware information systems but can also be used as reference for implementing time support in PAISs.     

VIVACE: A framework for the systematic evaluation of variability support in process-aware information systems

ContextThe increasing adoption of process-aware information systems (PAISs) such as workflow management systems, enterprise resource planning systems, or case management systems, together with the high variability in business processes (e.g., sales processes may vary depending on the respective products and countries), has resulted in large industrial process model repositories. To cope with this business process variability, the proper management of process variants along the entire process lifecycle becomes crucial.ObjectiveThe goal of this paper is to develop a fundamental understanding of business process variability. In particular, the paper will provide a framework for assessing and comparing process variability approaches and the support they provide for the different phases of the business process lifecycle (i.e., process analysis and design, configuration, enactment, diagnosis, and evolution).MethodWe conducted a systematic literature review (SLR) in order to discover how process variability is supported by existing approaches.ResultsThe SLR resulted in 63 primary studies which were deeply analyzed. Based on this analysis, we derived the VIVACE framework. VIVACE allows assessing the expressiveness of a process modeling language regarding the explicit specification of process variability. Furthermore, the support provided by a process-aware information system to properly deal with process model variants can be assessed with VIVACE as well.ConclusionsVIVACE provides an empirically-grounded framework for process engineers that enables them to evaluate existing process variability approaches as well as to select that variability approach meeting their requirements best. Finally, it helps process engineers in implementing PAISs supporting process variability along the entire process lifecycle.     

过程实例跃迁正确性判定准则研究

过程模型的动态更改会引起运行中的过程实例向更改后的过程模型跃迁,必须保证过程实例跃迁后运行的一致性。由于多分支结构的影响,不同过程实例的跃迁条件不易确定。研究了过程模型更改机制,通过删除、插入、修改三类元更改操作构造更改域。将过程执行历史能否重放作为过程实例跃迁正确性的判定准则,提出一种高效的过程实例精确跃迁条件评判方法,可以确定拥有不同路由结构、不同运行状态的过程实例的跃迁策略。该方法能适应多分支的过程模型,灵活性高,便于实现过程模型动态更改和实例跃迁的自动化。     

Model-driven specification and enforcement of RBAC break-glass policies for process-aware information systems

ContextIn many organizational environments critical tasks exist which – in exceptional cases such as an emergency – must be performed by a subject although he/she is usually not authorized to perform these tasks. Break-glass policies have been introduced as a sophisticated exception handling mechanism to resolve such situations. They enable certain subjects to break or override the standard access control policies of an information system in a controlled manner.ObjectiveIn the context of business process modeling a number of approaches exist that allow for the formal specification and modeling of process-related access control concepts. However, corresponding support for break-glass policies is still missing. In this paper, we aim at specifying a break-glass extension for process-related role-based access control (RBAC) models.MethodWe use model-driven development (MDD) techniques to provide an integrated, tool-supported approach for the definition and enforcement of break-glass policies in process-aware information systems. In particular, we provide modeling support on the computation independent model (CIM) layer as well as on the platform independent model (PIM) and platform specific model (PSM) layers.ResultsOur approach is generic in the sense that it can be used to extend process-aware information systems or process modeling languages with support for process-related RBAC and corresponding break-glass policies. Based on the formal CIM layer metamodel, we present a UML extension on the PIM layer that allows for the integrated modeling of processes and process-related break-glass policies via extended UML Activity diagrams. We evaluated our approach in a case study on real-world processes. Moreover, we implemented our approach at the PSM layer as an extension to the BusinessActivity library and runtime engine.ConclusionOur integrated modeling approach for process-related break-glass policies allows for specifying break-glass rules in process-aware information systems.     

Workflow evolution

A basic step towards flexibility in workflow systems is the consistent and effective management of workflow evolution, i.e. of changing existing workflows while they are operational. One of the most challenging issue is the handling of running instances when their schemata are modified: simple solutions can be devised, but they often imply losing all the work done or failing in capturing the advantages offered by workflow modifications; this is unacceptable for many applications. In this paper we address the problem of workflow evolution, from both a static and a dynamic point of view. We define a complete, minimal, and consistent set of modification primitives that allow modifications of workflow schemata and we introduce a taxonomy of policies to manage evolution of running instances when the corresponding workflow schema is modified. Formal criteria are introduced, based on a simple workflow conceptual model, in order to determine which running instances can be transparently migrated to the new version. A case study, relating the assembling of a desktop computer, will exemplify the introduced concepts.     

管理过程控制系统：工作流思想的一种新的应用模式

提出的管理过程控制系统将工作流思想应用于较低层次的管理支撑层。它采用面向信息流框架的机制来定义、协调、监督和控制管理过程,并使系统本身能独立于应用系统而存在,从而解放了应用系统的开发环境,摆脱了复杂、动态的流程和传统工作流管理系统中受过程定义模型约束的限制。该系统还具有运行时间步协作、信息继承和基于过程实例的动态流程控制的功能,可以作为企业信息设施的一个基础部件,支持工作流在复杂过程管理环境中的应用。     

Variability patterns for business processes in BPMN

Many entities, both in academia and the business sector, urge an efficient improvement of business processes. However, when it comes to addressing this point, each slight disparity in the business rules and/or objectives translates into a separate model, which is neither practical nor acceptable as it burdens the host process-aware information system with repetitive and almost verbatim instances. To solve this issue, we propose considering variability. Variability will serve as a business process improvement technique to efficiently design and run a variable business process throughout different business situations that are similar to one another is some ways yet differ in others. First, we define variability within the context of business processes. Second, we present a set of variability patterns and explain how they are used. We validate our approach via the business process improvement patterns known and used by the community. The variability design patterns are a series of business process improvement patterns for building business process with variability and efficiently acting on the improved process performance metrics.     

Process mining using BPMN: relating event logs and process models

Process-aware information systems (PAIS) are systems relying on processes, which involve human and software resources to achieve concrete goals. There is a need to develop approaches for modeling, analysis, improvement and monitoring processes within PAIS. These approaches include process mining techniques used to discover process models from event logs, find log and model deviations, and analyze performance characteristics of processes. The representational bias (a way to model processes) plays an important role in process mining. The BPMN 2.0 (Business Process Model and Notation) standard is widely used and allows to build conventional and understandable process models. In addition to the flat control flow perspective, subprocesses, data flows, resources can be integrated within one BPMN diagram. This makes BPMN very attractive for both process miners and business users, since the control flow perspective can be integrated with data and resource perspectives discovered from event logs. In this paper, we describe and justify robust control flow conversion algorithms, which provide the basis for more advanced BPMN-based discovery and conformance checking algorithms. Thus, on the basis of these conversion algorithms low-level models (such as Petri nets, causal nets and process trees) discovered from event logs using existing approaches can be represented in terms of BPMN. Moreover, we establish behavioral relations between Petri nets and BPMN models and use them to adopt existing conformance checking and performance analysis techniques in order to visualize conformance and performance information within a BPMN diagram. We believe that the results presented in this paper can be used for a wide variety of BPMN mining and conformance checking algorithms. We also provide metrics for the processes discovered before and after the conversion to BPMN structures. Cases for which conversion algorithms produce more compact or more complicated BPMN models in comparison with the initial models are identified.     

基于虚拟执行的动态工作流演进算法

为实现工作流管理系统中工作流演进的控制,解决流程实例动态调整的问题,给出工作流模型相关定义的形式化表示及正确性标准,提出基于数据流相关信息历史记录的虚拟执行算法,适用于模型结构变化及模型存在循环结构等情况.该算法能判断流程实例能否迁移,通过回退和撤销的策略保证工作流实例快速迁移.具体应用实例证明了迁移算法的正确性与可行...     

基于服务协作中间件的动态流程模型

新兴的面向服务体系结构正在加速软件的发展和变化,无法适应动态环境的应用将逐渐失去作用,尤其对那些面临着需求频繁变更的业务流程管理系统而言更是如此.为了响应这种现实需求,基于Web服务和业务流程管理技术,提出了服务协作中间件(service cooperation middleware,简称SCM)模型,探讨了其内部机理与协作流程元模型的形式化.通过引入模型转换,扩充流程状态空间,定义了动态流程模型,动态流程的结构重构和行为自适应可以借助SCM的反射能力得以实现.针对SCM模型,设计了流程虚拟机(prrocess virtual machine,简称PVM),流程在运行时由PVM控制执行.借助于模型驱动机制,业务流程可从设计到运行不断地进行模型变换.由此建立的业务流程能够更灵活、更广泛地适用于各种开放环境,提升企业分布计算.