Verification of workflow nets with transition conditions

Workflow management is concerned with automated support for business processes.Workflow management systems are driven by process models specifying the tasks that need to be executed,the order in which they can be executed,which resources are authorised to perform which tasks,and data that is required for,and produced by,these tasks.As workflow instances may run over a sustained period of time,it is important that workflow specifications be checked before they are deployed.Workflow verification is usually concerned with control-flow dependencies only;however,transition conditions based on data may further restrict possible choices between tasks.In this paper we extend workflow nets where transitions have concrete conditions associated with them,called WTC-nets.We then demonstrate that we can determine which execution paths of a WTC-net that are possible according to the control-flow dependencies,are actually possible when considering the conditions based on data.Thus,we are able to more accurately determine at design time whether a workflow net with transition conditions is sound.     

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.     

Verifying task-based specifications in conceptual graphs

A conceptual model is a model of real world concepts and application domains as perceived by users and developers. It helps developers investigate and represent the semantics of the problem domain, as well as communicate among themselves and with users. In this paper, we propose the use of task-based specifications in conceptual graphs (TBCG) to construct and verify a conceptual model. Task-based specification methodology is used to serve as the mechanism to structure the knowledge captured in the conceptual model; whereas conceptual graphs are adopted as the formalism to express task-based specifications and to provide a reasoning capability for the purpose of verification. Verifying a conceptual model is performed on model specifications of a task through constraints satisfaction and relaxation techniques, and on process specifications of the task based on operators and rules of inference inherited in conceptual graphs.     

An incremental analysis for resource conflicts to workflow specifications

Workflow management technology helps modulizing and controlling complex business processes within an enterprise. Generally speaking, a workflow management system (WfMS) is composed of two primary components, a design environment and a run-time system. Structural, timing and resource verifications of a workflow specification are required to assure the correctness of the specified system. In this paper, an incremental methodology is constructed to analyze resource consistency and temporal constraints after each edit unit defined on a workflow specification. The methodology introduces several algorithms for general and temporal analyses. The output returned right away can improve the judgment and thus the speed and quality on designing.     

工作流中时序约束正确性验证

分析了工作流管理系统中主要应该考虑的时间问题,然后建立了一个工作流时序条件有向图模型,在该模型基础上进行了一些关于时序逻辑推理问题的研究,提出了4个推理规则,同时提出了验证工作流活动时间约束正确性的一些必要条件。研究结果表明,所作的工作对于工作流管理系统的时间建模,监控和性能评价有一定的参考价值。     

一种基于Petri网的时间工作流模型的研究与验证

时间管理是工作流管理软件的重要部分,针对目前工作流系统对时间管理的需求,通过对传统Petri网扩展时间信息来描述时间模型,提出了一种静态验证方法,对模型进行基本验证和任务间的依赖约束验证;实例分析表明,该方法在减少工作量的同时提高了验证的有效性。     

基于交互学习的柔性工作流形式化验证方法研究

工作流过程建模是一个复杂且易错的过程,在建模阶段进行有效的过程验证是十分必要的。目前,柔性工作流验证领域的研究还比较欠缺,该文在这方面作了一些探索。把过程合理化验证和化简验证技术应用于基于交互学习的柔性工作流建模的形式化验证中,叙述了需要验证的问题和复杂度。利用Petri网的形式化基础特性对过程进行合理性验证和规约验证。根据规约粒度的不同,分别对基于交互学习的柔性工作流模型进行原子级和组件级规约。规约使用的基本技术有库所融合、变迁融合和子网融合。在特性保持的前提下,将过程模型缩小到适当规模。结果表明,基于交互学习的柔性工作流过程建模中的形式化验证方法具有一定的实用性和可操作性。     

Verifying minimum stable circuit values

We study properties of the minimum stable circuit value of a certain class of arithmetic circuits and describe a polynomial time algorithm that checks if a given circuit value is minimum stable for any such circuit.     

Constraint-centric workflow change analytics

In a globalized economic environment with volatile business requirements, continuous process improvement needs to be done regularly in various organizations. However, maintaining the consistency of workflow models under frequent changes is a significant challenge in the management of corporate information services. Unfortunately, few formal approaches are found in the literature for managing workflow changes systematically. In this paper, we propose an analytical framework for workflow change management through formal modeling of workflow constraints, leading to an approach called Constraint-centric Workflow Change Analytics (CWCA). A core component of CWCA is the formal definition and analysis of workflow change anomalies. We operationalize CWCA by developing a change anomaly detection algorithm and validate it in the context of procurement management. A prototype system based on an open-source rule engine is presented to provide a proof-of-concept implementation of CWCA.     

一种过程定义模型及其验证性分析

软件过程是管理、开发、维护软件系统所需要的一系列活动的偏序集合。软件过程作为一种工作流,其建模和分析可以采用工作流的理论和技术作为支撑。因为任务控制流的图示表示办法直观方便,因此大多系统都采用这种定义方式为软件过程建模。而过程定义的合理性验证问题复杂度通常是非常高的,必须寻求合理的算法。图规约算法就是一种实际可行的算法。