BPMN 2.0过程模型的语义和分析

BPMN 2.0已成为了建模业务过程事实上的标准。BPMN 2.0过程模型中建模元素的混用会产生控制流方面的语义错误。首先,建立了BPMN 2.0过程模型到工作流网的映射,并使用Petri网来形式定义过程模型的语义;其次,借助Petri网的分析技术,使用这种定义的语义对BPMN 2.0过程模型进行了合理性分析。实验结果表明,这种形式化可以识别BPMN 2.0过程模型中的语义错误。     

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.     

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。     

一种基于语义描述的Web应用构件自动组装与实现方法

构件组装技术是一种将已有的可复用构件遵循特定的组装方案进行组合的技术,组装的结果是一个粒度更大的构件或者是一个完整的应用系统。然而,现有的技术还难以自动组装那些涉及在线人工交互操作的Web应用构件。针对这个问题,提出一种基于语义描述的Web应用构件自动组装与实现方法。该方法首先提出一种扩展OWL-S的针对Web应用构件及其组装的语义化描述方案。基于该描述,可根据用户的应用需求按照匹配规则从众多构件中筛选出符合需求语义描述的Web应用构件。另外,该方法还提出一种OWL-S到符合BPMN2.0标准的映射方案,用于将描述Web应用构件及其组装方式的OWL-S映射为BPMN2.0文件。j BPM流程引擎可加载并解释执行该BPMN文件,从而实现Web应用构件的自动组装与运行。最后,通过一个旅行规划的实例验证了该方法的可行性和有效性。     

基于相似度特征的Web服务匹配算法

针对Web服务查找与匹配困难问题,提出一种基于Petri网和QOS计算的Web服务模糊匹配算法.构建OWL-S过程模型,依靠该模型中的控制流、状态转移与信息转换,将Web服务以Petri网的形式表示,利用节点、网络架构与变迁的语义标准计算Petri网相似度,获取Petri网参数的最优匹配子图,通过计算Petri网的输出...     

基于属性Petri网的语义网络知识表示

首先给出了基于定性映射的属性Petri网的形式定义和运行机制;其次给出了基于属性Petri网的语义网络知识表示模式,此模式适合干感觉特征抽取与整合,和基于该机制的各种思维功能的描述。     

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。     

基于概率和时间因素的Petri网业务流程一致性分析

业务流程一致性分析作为业务流程管理的重要内容之一,近年来一直是业务流程管理研究领域的热点。目前已有的方法主要从控制流和数据流两方面进行研究,在实际情况下,概率和时间因素会对业务流程产生较大的影响。因此,文中提出了一种基于概率和时间因素的Petri网业务流程一致性分析方法。首先,给出了基于概率因素的控制流Petri网和基于时间因素的数据流Petri网的定义;然后,将基于概率因素的控制流Petri网和基于时间因素的数据流Petri网中的所有变迁分别映射到原业务流程Petri网中,得到各自的行为映射表,并针对两种类型的Petri网提出相应的行为兼容度算法,依据行为兼容度的值来衡量业务流程的一致性程度;最后,进行实例分析,结果显示了该方法的有效性和优越性。     

程序代码中隐含数据与控制的Petri 网建模技术

应用一种Petri网扩展CNets,描述程序代码中所隐含着的数据与控制,分别给出了程序代码的数据视图和控制视图.在CNets规范的基础上,研究程序中的数据与控制流之间的交互以及程序中数据、操作和资源之间的关系,同时给出CNets规范向经典Petri网规范的转换规则.在不运行程序的前提下,根据这一映射机制,通过CNets规范,利用经典Petri网理论对程序的性质进行分析.     

一种保持编排与参与者间行为一致的映射方法

将编排映射为Peer（参与者）,是对编排进行可实现性分析的第1个步骤.现有文献提出的映射方法未考虑参与者中τ对行为的影响,无法确保编排与参与者间的行为一致性.以Petri网作为形式化基础,提出了一种能够保持编排与参与者间行为一致的映射方法,允许：（1）通过动作映射,将交互式Petri网定义的编排映射为带τ的交互式Petri网;（2）提出了4条τ删除规则,用以对带τ的交互式Petri网中的τ进行有选择的删除;（3）将编排与参与者间的行为一致性问题规约为检验两个交互式Petri间是否满足弱互模拟的问题,并证明了这4条τ删除规则的正确性.实验结果表明,该映射方法能够确保编排与参与者间的行为一致性.     

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.     

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.     

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.     

VPM: A visual,precise and multilevel metamodeling framework for describing mathematical domains and UML (The Mathematics of Metamodeling is Metamodeling Mathematics)

As UML 2.0 is evolving into a family of languages with individually specified semantics, there is an increasing need for automated and provenly correct model transformations that (i) assure the integration of local views (different diagrams) of the system into a consistent global view, and, (ii) provide a well-founded mapping from UML models to different semantic domains (Petri nets, Kripke automaton, process algebras, etc.) for formal analysis purposes as foreseen, for instance, in submissions for the OMG RFP for Schedulability, Performance and Time. However, such transformations into different semantic domains typically require the deep understanding of the underlying mathematics, which hinders the use of formal specification techniques in industrial applications. In the paper, we propose a multilevel metamodeling technique with precise static and dynamic semantics (based on a refinement calculus and graph transformation) where the structure and operational semantics of mathematical models can be defined in a UML notation without cumbersome mathematical formulae.     

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。     

A visual token-based formalization of BPMN 2.0 based on in-place transformations

ContextThe Business Process Model and Notation (BPMN) standard informally defines a precise execution semantics. It defines how process instances should be updated in a model during execution. Existing formalizations of the standard are incomplete and rely on mappings to other languages.ObjectiveThis paper provides a BPMN 2.0 semantics formalization that is more complete and intuitive than existing formalizations.MethodThe formalization consists of in-place graph transformation rules that are documented visually using BPMN syntax. In-place transformations update models directly and do not require mappings to other languages. We have used a mature tool and test-suite to develop a reference implementation of all rules.ResultsOur formalization is a promising complement to the standard, in particular because all rules have been extensively verified and because conceptual validation is facilitated (the informal semantics also describes in-place updates).ConclusionSince our formalization has already revealed problems with the standard and since the BPMN is still evolving, the maintainers of the standard can benefit from our results. Moreover, tool vendors can use our formalization and reference implementation for verifying conformance to the standard.     

The rewriting logic semantics project

Rewriting logic is a flexible and expressive logical framework that unifies algebraic denotational semantics and structural operational semantics (SOS) in a novel way, avoiding their respective limitations and allowing succinct semantic definitions. The fact that a rewrite logic theory’s axioms include both equations and rewrite rules provides a useful “abstraction dial” to find the right balance between abstraction and computational observability in semantic definitions. Such semantic definitions are directly executable as interpreters in a rewriting logic language such as Maude, whose generic formal tools can be used to endow those interpreters with powerful program analysis capabilities.