BPMN 2.0编排的形式语义和分析

BPMN 2.0编排已成为描述业务流程间交互事实上的标准.BPMN 2.0编排面向流的特征,使之会产生控制流方面的语义错误.因此,检查编排语义正确性是BPMN 2.0编排建模工具所期望具有的功能.但是,BPMN 2.0标准规约中编排缺少形式语义及相应的分析技术,这阻碍了对BPMN 2.0编排的语义分析.本文提出了一种映射,用于将BPMN 2.0编排转换为工作流网,使用Petri网来形式定义BPMN 2.0编排的语义.借助Petri网的分析技术,这种定义的语义可用来分析BPMN 2.0编排的结构和控制流方面的错误.该映射和语义分析已被实现为一种工具.实验结果表明,这种形式化可以识别BPM AI过程模型库中编排的语义错误.     

时间Petri网弱语义模型的形式化分析

时间Petri网存在强语义和弱语义两种模型,弱语义模型更适合建模和分析外部环境触发的冲突选择问题,但其形式语义和可达性分析方面的研究,却很少有人问津。利用带标号的变迁系统定义时间Petri网弱语义模型的形式语义,采用时间戳状态类方法分析它的可达性,并证明了可达性问题的可判性和状态类时间戳的全局时间性质。     

基于一种新型混杂Petri网的混杂系统建模与控制

为了增强混杂Petri网模型描述能力和克服一阶混杂Petri网模型语义错误的问题，定义一种新的混杂Petri网模型——广义混杂Petri网，提出了相应的迁移使能和迁移引发语义．通过划分标识等价类提出了广义混杂Petri网连续迁移瞬时引发速率的有效求解方法和模型行为演变分析方法．给出了广义混杂Petri网模型的混杂系统建模实例，同时结合模型行为演变和线性规划实现了混杂系统的优化控制．研究结果表明，所定义的模型描述能力更强，模型语义正确合理．能够有效描述和分析混杂系统．     

应急预案流程的Petri网建模方法研究

为了提高应急信息系统模型的语义基础,提出了一种基于Petri网的应急预案流程的建模方法。以ABC模型为上位本体建立了应急预案流程本体,提出了应急预案流程的Petri网建模过程,并定义了应急预案流程中本体和层次Petri网的映射规则。使用该方法对某公路桥梁抢修应急预案流程进行Petri网建模,并通过仿真分析验证了建模方法的有效性。     

语义标记Petri网的组合Web服务建模与验证(英文)

随着Web服务组合的发展,整合业务过程成为可能。组合Web服务可以被看作是基于过程的工作流。由于死锁、不安全和不可达等流的设计错误会影响组合Web服务的有效执行,因此这些错误应在组合Web服务执行前被检测出并修改。提出了基于语义标记Petri网的组合Web服务建模与验证方法。首先提出语义标记Petri网(SaPNs),并给出其语义;用受限描述逻辑tableau算法获得组合Web服务;使用SaPNs描述组合Web服务及其组成部分;最后,使用基于SaPNs的分析方法验证了组合Web服务。使用该方法在开放的Internet环境下可以获得满足客户需求的、可靠的组合Web服务。     

基于扩展Petri网模型的BPMN形式化

BPMN(Business Process Modeling Notation)作为一个在系统开发早期阶段获取业务过程模型的标准,指导系统的设计和开发,其模型的正确性是影响软件开发质量的关键。鉴于BPMN模型的形式化可以验证模型的正确性,提出了一种利用扩展Petri网模型,应用模型驱动技术实现BPMN模型形式化自动执行的方法。该方法通过细化Petri网模型中的Transition和Place元素以及增加Organization Identifier和Group Identifier容器,使其不但能够描述BPMN模型中的动态行为,而且还能描述BPMN模型中的动态行为协作和静态组织结构。从元模型结构、语法和图标记方面详细分析了扩展的Petri网模型元素,利用模型驱动开发技术设计BPMN模型元素至扩展的Petri网模型元素的转换规则,并在Eclipse平台上使用ATL模型转换语言执行映射,实现形式化的自动执行。最后在此基础上应用Travel Agency系统演示了模型形式化插件BPMN2ExtendPetrinets的执行结果。     

UML2.0顺序图的形式化研究

在UML2.0规范中顺序图的语义仍然是以自然语言的形式描述的,为实现对顺序图的自动化分析和验证,必须为顺序图定义一种形式化的语义模型.为此首先给出了UML顺序图的一种符合BNF范式的形式化语法,然后为该语法中的非终止符定义转换规则,将UML顺序图中的基本动作转换为加标Petri网组件,最后定义了各种合成操作,利用这些合成操作可以将UML顺序图的加标Petri网组件转换为加标Petni网.     

基于petri网的语义Web服务过程模型匹配算法研究

为了在服务发现中提高效率及准确率,在服务匹配过程中引入了服务执行状态的变迁等因素即服务的过程模型。而Petri网能够把Web服务的过程模型进行形式化描述。该文在服务发现中引入Petri网,通过Petri网描述Web服务的过程模型,再对Petri网进行语义标注,最后通过计算过程模型的相似度来实现基于Petfi网的语义Web服务发现匹配。这种方法结合现有采用功能性参数匹配的语义web服务发现对提高服务发现率,尤其对改善服务发现准确率起到了一定的作用。     

基于Petri 网和语义网络的虚拟维修过程建模与应用

针对当前虚拟维修过程中模型庞大,维修流程不可反复,部件间关系描述 混乱等问题,论文提出一种Petri 网和语义网络结合的过程建模方法——TJ(Training Join)网。 TJ 网上层利用语义网络对部件进行层次结构分解和资源规范聚类,实现子部件间逻辑互联; 下层运用Petri 网的变迁和触发规则提炼出Petri 网元素模型,提高模型的通用性和建模效率。 同时模型中的状态收集模块可实现部件属性状态间信息共享。最后,以虚拟维修平台中飞机 电子设备架的维护为例,验证了TJ 网的有效性。     

基于PTCPN的网构软件建模与分析

时间Petri网能够对网构软件的性能进行分析,但是无法对网构软件的可变代价进行分析.为了进一步满足对网构软件所具有的柔性建模以及可变代价分析的需求,提出一种代价时间有色Petri网模型(price time colored Petri net,简称PTCPN).该模型对时间Petri网进行了可变代价和颜色信息的扩展,并使用代价时间变迁系统定义了PTCPN的语义;定义了PTCPN的累积代价状态类,并证明了累积代价状态类的合理性和完备性;给出了基于PTCPN的多Agent网构软件建模及分析方法.最后,通过实例分析说明应用PCTPN对网构软件进行形式化建模及分析是可行的.     

Semantics and analysis of business process models in BPMN

The Business Process Modelling Notation (BPMN) is a standard for capturing business processes in the early phases of systems development. The mix of constructs found in BPMN makes it possible to create models with semantic errors. Such errors are especially serious, because errors in the early phases of systems development are among the most costly and hardest to correct. The ability to statically check the semantic correctness of models is thus a desirable feature for modelling tools based on BPMN. Accordingly, this paper proposes a mapping from BPMN to a formal language, namely Petri nets, for which efficient analysis techniques are available. The proposed mapping has been implemented as a tool that, in conjunction with existing Petri net-based tools, enables the static analysis of BPMN models. The formalisation also led to the identification of deficiencies in the BPMN standard specification.     

基于BPMN的服务组合执行引擎的研究与实现*

业务模型和执行模型的一致性是当前服务组合研究的一个难点和热点。目前普遍采用模型转换的方式将业务模型映射为可执行模型,但由于两种模型语言的语义和语法不一致,导致了模型转换存在语义失配等缺陷。针对该问题,提出了一种基于业务流程建模标注的Web服务组合执行方案,设计了BPMN模型的解释执行算法,给出了执行引擎的原型系统,并通过具体案例验证了方案的有效性。     

Property specifications for workflow modelling

Previously we provided two formal behavioural semantics for the Business Process Modelling Notation (BPMN) in the process algebra CSP. By exploiting CSP’s refinement orderings, developers may formally compare their BPMN models. However, BPMN is not a specification language, and it is difficult and sometimes impossible to use it to construct behavioural properties against which other BPMN models may be verified. This paper considers a pattern-based approach to expressing behavioural properties. We describe a property specification language PL for capturing a generalisation of Dwyer et al.’s Property Specification Patterns, and present a translation from PL into a bounded, positive fragment of linear temporal logic, which can then be automatically translated into CSP for simple refinement checking. We present a detailed example studying the behavioural properties of an airline ticket reservation business process. Using the same example we also describe some recent results on expressing behavioural compatibility within our semantic models. These results lead to a compositional approach for ensuring deadlock freedom of interacting business processes.     

Semantische Prozessmodellierung – Konzeption und informationstechnische Unterstützung einer ontologiebasierten Repräsentation von Geschäftsprozessen

An extension of process modeling languages is designed which allows representing the semantics of model element labels which are formulated in natural language by using concepts of a formal ontology. This combination of semiformal models with formal ontologies will be characterized as semantic process modeling. The approach is exemplarily applied to the languages EPC (Event-driven Process Chain), BPMN (Business Process Modeling Notation) and OWL (Web Ontology Language) and is generalized by means of an information model. The proposed formalization of the semantics of individual model elements in conjunction with the usage of inference engines allows the improvement of query functionalities in modeling tools and enables new possibilities of model validation. The integration of the approach in the IT-based work environments of modelers is demonstrated by a system architecture and a prototypical implementation. Evidently, advantages in the areas of modeling, model management, business/IT alignment, and compliance can be achieved by the application of modeling tools augmented with semantic technologies.     

A metamodel to integrate business processes time perspective in BPMN 2.0

ContextBusiness Process Management (BPM) is becoming a strategic advantage for organizations to streamline their operations. Most business experts are betting for OMG Business Process Model and Notation (BPMN) as de-facto standard (ISO/IEC 19510:2013) and selected technology to model processes. The temporal dimension underlies in any kind of process however, technicians need to shape this perspective that must also coexist with task control flow aspects, as well as resource and case perspectives. BPMN poorly gathers temporary rules. This is why there are contributions that extend the standard to cover such dimension. BPMN is mainly an imperative language. There are research contributions showing time constraints in BPMN, such as (i) BPMN patterns to express each rule with a combination of artifacts, thus these approaches increase the use of imperative BPMN style, and (ii) new decorators to capture time rules semantics giving clearer and simpler comprehensible specifications. Nevertheless, these extensions cannot yet be found in the present standard.ObjectiveTo define a time rule taxonomy easily found in most business processes and look for an approach that applies each rule with current BPMN 2.0 standard in a declarative way.MethodA model-driven approach is used to propose a BPMN metamodel extension to address time-perspective.ResultsWe look at a declarative approach where new time specifications may overlie the main control flow of a BPMN process. This proposal is totally supported with current BPMN standard, giving a BPMN metamodel extension with OCL constraints. We also use AQUA-WS as a software project case study which is planned and managed with MS Project. We illustrate business process extraction from project plans.ConclusionThis paper suggests to handle business temporal rules with current BPMN standard, along with other business perspectives like resources and cases. This approach can be applied to reverse engineering processes from legacy databases.     

Formalisations and applications of BPMN

We present two formalisations of the Business Process Modelling Notation (BPMN). In particular, we introduce a semantic model for BPMN in the process algebra CSP; we then study an augmentation of this model in which we introduce relative timing information, allowing one to specify timing constraints on concurrent activities. By exploiting CSP refinement, we are able to show some relationships between the timed and the untimed models. We then describe a novel empirical studies’ model, and the transformation to BPMN, allowing one to apply our formal semantics for analysing different kinds of workflows. To provide a better facility for describing behaviour specification about a BPMN diagram, we also present a pattern-based approach using which a workflow designer could specify properties which could otherwise be difficult to express. Our approach is specifically designed to allow behavioural properties of BPMN diagrams to be mechanically verified via automatic model checking as provided by the FDR tool. We use two examples to illustrate our approach.     

Modeling functional requirements for configurable content- and context-aware dynamic service selection in business process models

In this article, we propose a meta-model for formal specification of functional requirements for configurable content- and context-aware dynamic service selection in business process models with the objective to enable greater flexibility of the modeled processes. The dynamic service selection can cope with highly dynamic business environments that today's business processes must handle. Modeling functional requirements for dynamic service selection in business process models is not well covered in literature. Some partial solutions exist but none of them allows modeling a complete set of functional requirements for the selection similar to the one we are addressing in this article. Our meta-model enables formal specification of service selection relevant data extracted from service request message, custom configuration data (e.g., thresholds), process and task definition/instance metadata, and service selection rules. The meta-model is configurable and content- and context-aware. Processes leveraging our meta-model can adapt to changing requirements without redesign of the process flow. Proposed meta-model allows users to additionally configure the models at run time (e.g., raising a threshold). Modeling can be divided into roles with different required competences. We implement our meta-model in BPMN 2.0 (Business Process Model and Notation) through specific extensions to the BPMN semantic and diagram elements. By measuring complexity of real-world sample process models we show that using our solution modelers can efficiently model business processes that need to address frequent changing demands. Compared to available alternatives, models using our solution have on average ～13% fewer activities, ～16% fewer control-flow elements and ～22% fewer control paths. By reading ～10% smaller models (by volume) model readers get more flexible process models that capture all functional requirements for the dynamic selection.     

BPMNt: A BPMN extension for specifying software process tailoring

ContextAlthough SPEM 2.0 has great potential for software process modeling, it does not provide concepts or formalisms for precise modeling of process behavior. Indeed, SPEM fails to address process simulation, execution, monitoring and analysis, which are important activities in process management. On the other hand, BPMN 2.0 is a widely used notation to model business processes that has associated tools and techniques to facilitate the aforementioned process management activities. Using BPMN to model software development processes can leverage BPMN’s infrastructure to improve the quality of these processes. However, BPMN lacks an important feature to model software processes: a mechanism to represent process tailoring.ObjectiveThis paper proposes BPMNt, a conservative extension to BPMN that aims at creating a tailoring representation mechanism similar to the one found in SPEM 2.0.MethodWe have used the BPMN 2.0 extensibility mechanism to include the representation of specific tailoring relationships namely suppression, local contribution, and local replacement, which establish links between process elements (such as in the case of SPEM). Moreover, this paper also presents some rules to ensure the consistency of BPMN models when using tailoring relationships.ResultsIn order to evaluate our proposal we have implemented a tool to support the BPMNt approach and have applied it for representing real process adaptations in the context of an academic management system development project. Results of this study showed that the approach and its support tool can successfully be used to adapt BPMN-based software processes in real scenarios.ConclusionWe have proposed an approach to enable reuse and adaptation of BPMN-based software process models as well as derivation traceability between models through tailoring relationships. We believe that bringing such capabilities into BPMN will open new perspectives to software process management.