Nowadays an increasing number of workflow products and research prototypes begin to adopt XML for representing workflow models owing to its easy use and well understanding for people and machines. However, most of wor...Nowadays an increasing number of workflow products and research prototypes begin to adopt XML for representing workflow models owing to its easy use and well understanding for people and machines. However, most of workflow products and research prototypes provide the few supports for the verification of XML-based workflow model, such as free-deadlock properties, which is essential to successful application of workflow technology. In this paper, we tackle this problem by mapping the XML-based workflow model into Petri-net, a kind of well-known formalism for modeling, analyzing and verifying system. As a result, the XML-based workflow model can be automatically verified with the help of general Petri-net tools, such as DANAMICS. The presented approach not only enables end users to represent workflow model with XML-based modeling language, but also the correctness of model can be ensured, thus satisfying the needs of business processes.展开更多
The soundness is a very important criterion for the correctness of the workflow. Specifying the soundness with Computation Tree Logic （CTL） allows us to verify the soundness with symbolic model checkers. Therefore t...The soundness is a very important criterion for the correctness of the workflow. Specifying the soundness with Computation Tree Logic （CTL） allows us to verify the soundness with symbolic model checkers. Therefore the state explosion problem in verifying soundness can be overcome efficiently. When the property is not satisfied by the system, model checking can give a counter-example, which can guide us to correct the workflow. In addition, relaxed soundness is another important criterion for the workflow. We also prove that Computation Tree Logic ＊ （CTL ＊ ） can be used to character the relaxed soundness of the workflow.展开更多
In many service delivery systems,the quantity of available resources is often a decisive factor of service quality.Resources can be personnel,offices,devices,supplies,and so on,depending on the nature of the services ...In many service delivery systems,the quantity of available resources is often a decisive factor of service quality.Resources can be personnel,offices,devices,supplies,and so on,depending on the nature of the services a system provides.Although service computing has been an active research topic for decades,general approaches that assess the impact of resource provisioning on service quality matrices in a rigorous way remain to be seen.Petri nets have been a popular formalism for modeling systems exhibiting behaviors of competition and concurrency for almost a half century.Stochastic timed Petri nets(STPN),an extension to regular Petri nets,are a powerful tool for system performance evaluation.However,we did not find any single existing STPN software tool that supports all timed transition firing policies and server types,not to mention resource provisioning and requirement analysis.This paper presents a generic and resource oriented STPN simulation engine that provides all critical features necessary for the analysis of service delivery system quality vs.resource provisioning.The power of the simulation system is illustrated by an application to emergency health care systems.展开更多
Workflow management aims at the controlling, monitoring, optimizing and supporting of business processes. Well designed formal models will facilitate such management since they provide explicit representations of busi...Workflow management aims at the controlling, monitoring, optimizing and supporting of business processes. Well designed formal models will facilitate such management since they provide explicit representations of business processes as the basis for computerized analysis, verification and execution. Petri Nets have been recognized as the most suitable candidate for workflow modeling, and as such, formal models based on Petri Nets have been proposed, among them WF-net by Aalst is the most popular one. But WF-net has turned out to be conceptually chaotic as will be illustrated in this paper with an example from Aalst＇s book. This paper proposes a series of models for the description and analysis of business processes at conceptually different hierarchical layers. Analytic goals and methods at these layers are also discussed. The underlying structure, shared by all these models, is SYNCHRONIZER, which is designed with the guidance of synchrony theory of GNT （General Net Theory） and serves as the conceptual foundation of workflow formal models. Structurally, synchronizers connect tasks to form a whole while dynamically synchronizers control tasks to achieve synchronization.展开更多
结合XPDL(XML Process Definition Language)标准、对象技术和Petri网理论提出了一种工作流网。该工作流网通过Petri网的数学分析来完成对流程的分析验证;通过对象技术来降低流程建模复杂度;通过工作流网和XPDL的映射机制来保证其实用...结合XPDL(XML Process Definition Language)标准、对象技术和Petri网理论提出了一种工作流网。该工作流网通过Petri网的数学分析来完成对流程的分析验证;通过对象技术来降低流程建模复杂度;通过工作流网和XPDL的映射机制来保证其实用性。在此基础上实现了一套流程建模及分析工具。展开更多
文摘Nowadays an increasing number of workflow products and research prototypes begin to adopt XML for representing workflow models owing to its easy use and well understanding for people and machines. However, most of workflow products and research prototypes provide the few supports for the verification of XML-based workflow model, such as free-deadlock properties, which is essential to successful application of workflow technology. In this paper, we tackle this problem by mapping the XML-based workflow model into Petri-net, a kind of well-known formalism for modeling, analyzing and verifying system. As a result, the XML-based workflow model can be automatically verified with the help of general Petri-net tools, such as DANAMICS. The presented approach not only enables end users to represent workflow model with XML-based modeling language, but also the correctness of model can be ensured, thus satisfying the needs of business processes.
基金Supported by the National Natural Science Foun-dation of China (60573046)
文摘The soundness is a very important criterion for the correctness of the workflow. Specifying the soundness with Computation Tree Logic （CTL） allows us to verify the soundness with symbolic model checkers. Therefore the state explosion problem in verifying soundness can be overcome efficiently. When the property is not satisfied by the system, model checking can give a counter-example, which can guide us to correct the workflow. In addition, relaxed soundness is another important criterion for the workflow. We also prove that Computation Tree Logic ＊ （CTL ＊ ） can be used to character the relaxed soundness of the workflow.
文摘In many service delivery systems,the quantity of available resources is often a decisive factor of service quality.Resources can be personnel,offices,devices,supplies,and so on,depending on the nature of the services a system provides.Although service computing has been an active research topic for decades,general approaches that assess the impact of resource provisioning on service quality matrices in a rigorous way remain to be seen.Petri nets have been a popular formalism for modeling systems exhibiting behaviors of competition and concurrency for almost a half century.Stochastic timed Petri nets(STPN),an extension to regular Petri nets,are a powerful tool for system performance evaluation.However,we did not find any single existing STPN software tool that supports all timed transition firing policies and server types,not to mention resource provisioning and requirement analysis.This paper presents a generic and resource oriented STPN simulation engine that provides all critical features necessary for the analysis of service delivery system quality vs.resource provisioning.The power of the simulation system is illustrated by an application to emergency health care systems.
基金Supported by the National Natural Science Foundation of China nnder Grant No.60473058the National Grand Fundamental Research 973 Program of China under Graut Nos.2002CB312004,2002CB312006.
文摘Workflow management aims at the controlling, monitoring, optimizing and supporting of business processes. Well designed formal models will facilitate such management since they provide explicit representations of business processes as the basis for computerized analysis, verification and execution. Petri Nets have been recognized as the most suitable candidate for workflow modeling, and as such, formal models based on Petri Nets have been proposed, among them WF-net by Aalst is the most popular one. But WF-net has turned out to be conceptually chaotic as will be illustrated in this paper with an example from Aalst＇s book. This paper proposes a series of models for the description and analysis of business processes at conceptually different hierarchical layers. Analytic goals and methods at these layers are also discussed. The underlying structure, shared by all these models, is SYNCHRONIZER, which is designed with the guidance of synchrony theory of GNT （General Net Theory） and serves as the conceptual foundation of workflow formal models. Structurally, synchronizers connect tasks to form a whole while dynamically synchronizers control tasks to achieve synchronization.
文摘结合XPDL(XML Process Definition Language)标准、对象技术和Petri网理论提出了一种工作流网。该工作流网通过Petri网的数学分析来完成对流程的分析验证;通过对象技术来降低流程建模复杂度;通过工作流网和XPDL的映射机制来保证其实用性。在此基础上实现了一套流程建模及分析工具。
