Remarks on Egon Börger: “Approaches to model business processes: a critical analysis of BPMN, workflow patterns and YAWL, SOSYM 11:305–318”

Egon Börger (SOSYM, 11, pp. 305–318, 2012) challenges the concepts of BPMN, workflow patterns and YAWL as useful contributions to the modeling of business processes. I show that he misjudges the role of BPMN, YAWL and similar techniques in the modeling of business processes. In particular he mistakes YAWL’s formal basis, i.e. Petri nets. Börger furthermore suggests evaluation criteria for business process modeling tools. I argue that his criteria overemphasize some less important aspects, while ignoring some decisive ones.     

YAWL: yet another workflow language

Based on a rigorous analysis of existing workflow management systems and workflow languages, a new workflow language is proposed: yet another workflow language (YAWL). To identify the differences between the various languages, we have collected a fairly complete set of workflow patterns. Based on these patterns we have evaluated several workflow products and detected considerable differences in their ability to capture control flows for non-trivial workflow processes. Languages based on Petri nets perform better when it comes to state-based workflow patterns. However, some patterns (e.g. involving multiple instances, complex synchronisations or non-local withdrawals) are not easy to map onto (high-level) Petri nets. This inspired us to develop a new language by taking Petri nets as a starting point and adding mechanisms to allow for a more direct and intuitive support of the workflow patterns identified. This paper motivates the need for such a language, specifies the semantics of the language, and shows that soundness can be verified in a compositional way. Although YAWL is intended as a complete workflow language, the focus of this paper is limited to the control-flow perspective.     

Bundle and Pool Architecture for Multi-Language, Robust, Scalable Workflow Executions

In this paper, we leverage the previous work on the SHIWA bundling format and expand on this specification in order to facilitate workflow execution within a multi-workflow environment. We introduce a scalable and robust execution pool environment that supports workflows consisting of sub-workflows built upon a multitude of different workflow engines and environments, and also provide a common workflow representation for seamless connectivity through serialization to workflow bundles. We also present a meta-workflow scenario based upon this system. Workflow bundles employ the lightweight Open Archives Initiative Object Reuse and Exchange (ORE) Web-based standard, to provide a common format for representing and sharing workflows and the associated metadata required for their execution. This generalized bundling approach is already available within five workflow engines and has proven a useful environment for inter-workflow experimentation. The execution pool facilitates federated access to multiple distributed computing infrastructures supported by the underlying workflow engines subscribed to the pool. Workflow bundles are exposed using the eXtensible Messaging and Presence Protocol (XMPP), which provides the necessary communication backbone to enable multiple workflow engine agents to asynchronously publish and subscribe to bundles in meta-workflow pipelines. We present experiments showing the scalability and robustness of the pool execution approach with results showing that overheads remain controlled for up to 150 workflow agents, and that agent failures have very limited impact. We then demonstrate the applicability of our architecture by describing how a Java-based music analysis workflow can be distributed within such a multi-workflow environment consisting of the Triana and MOTEUR workflow engines.     

基于工作流网的银行业务库高安全门禁系统

银行业务库门禁系统是一种对安全要求极高的出入口控制系统,作为业务库的第一道安全防线,该系统比普通门禁拥有更多的约束条件、更复杂的流程。先对比普通门禁和业务库门禁系统,由此引出定理合理的工作流网中加入约束后仍然是合理的工作流网。然后通过工作流网对普通门禁和业务库门禁系统进行了系统模型的建立,再采用YAWL Editor工具分析了所构建系统的正确性,最后使用软硬件协同设计的方法改进并实现了业务库门禁系统。实验结果验证了定理的正确性,同时表明基于工作流网的方法有效降低了门禁系统的设计难度,并在具体实现之前确保了设计的正确性,提高了系统的开发效率。     

基于YAWL的商品安全消费系统建模与分析

关注商品消费安全是经济活动的迅猛发展的必然要求。在综合分析现有工作流建模技术的基础上,引入YAWL这一新技术,结合商品安全消费问题的特点,建立商品安全消费系统的YAWL模型。同时,应用YAWL的分析方法,以可达性分析说明建立YAWL模型对系统性能分析的优点。     

面向云计算的工作流技术

云计算的发展,对提高服务质量与压缩运行成本提出了新的要求.在此背景下,工作流技术被认为是一种较为优越的解决方案:从云计算用户的角度看,工作流提供了对复杂应用的抽象定义、灵活配置和自动化运行;从云计算服务提供者的角度看,工作流实现了任务的自动调度、资源的优化和管理.文章介绍工作流技术与云计算;阐述了云工作流产生的背景;深入剖析了云工作流的技术特征以及与其他工作流(业务工作流、网格工作流)的异同;列举了云工作流的4个实现案例,并对其进行比较.最后,在总结全文的同时,展望了云工作流技术的发展前景.     

Workflow-based semantics for peer-to-peer specifications

In this paper we introduce SMoL, a simplified BPEL-like language for specifying peer and service behaviour in P2P systems. We then define a transformational semantics of SMoL in terms of Yet Another Workflow Language (YAWL) workflows, which enables the simulation (e.g., testing possible execution scenarios) and analysis (e.g., verifying reachability or lock freedom) of the behaviour of P2P peers and services.     

用着色Petri网建模工作流模式

工作流模式指在工作流过程模型中反复出现的过程基本构造，是衡量工作流建模语言在控制流方面的表达能力和适用性的重要标准，目前市场上的工作流引擎对其支持得并不好。本文重点阐述了基于着色Petri网的工作流建模语言对当前流行的20种工作流模式的支持情况。结果表明，该语言不仅能很好地支持全部模式，而且具有建模简洁、准确的特点。同其它建模语言相比，用着色Petri网建模工作流模式具有较好的灵活性和扩展性。它也为如何使基于着色Petri网的工作流引擎能够正确、有效地支持全部20种工作流模式提供了有意义的指导。     

动态工作流挖掘模型及算法研究

工作流挖掘是工作流再设计与分析的一项关键技术,目的在于从企业已有信息系统的日志记录中提取与实际应用相关的业务流程,从而提高工作流建模的客观性。从实际应用的角度出发,提出基于动态工作流网的挖掘模型,并设计了可行的算法。该算法从零日志开始,在工作流执行期间柔性地构建工作流模型和生成日志记录,动态生成工作流网,在很大程度上解决了常规挖掘方法在挖掘复杂结构效率低、准确性差、依赖完整的日志记录和不支持柔性工作流等方面的问题。算法的实用性在实际应用系统中得到了很好的证明。