Discovering colored Petri nets from event logs

Process-aware information systems typically log events (e.g., in transaction logs or audit trails) related to the actual execution of business processes. Analysis of these execution logs may reveal important knowledge that can help organizations to improve the quality of their services. Starting from a process model, which can be discovered by conventional process mining algorithms, we analyze how data attributes influence the choices made in the process based on past process executions using decision mining, also referred to as decision point analysis. In this paper we describe how the resulting model (including the discovered data dependencies) can be represented as a Colored Petri Net (CPN), and how further perspectives, such as the performance and organizational perspective, can be incorporated. We also present a CPN Tools Export plug-in implemented within the ProM framework. Using this plug-in, simulation models in ProM obtained via a combination of various process mining techniques can be exported to CPN Tools. We believe that the combination of automatic discovery of process models using ProM and the simulation capabilities of CPN Tools offers an innovative way to improve business processes. The discovered process model describes reality better than most hand-crafted simulation models. Moreover, the simulation models are constructed in such a way that it is easy to explore various redesigns. A. Rozinat’s research was supported by the IOP program of the Dutch Ministry of Economic Affairs. M. Song’s research was supported by the Technology Foundation STW.     

改进型有色Petri网的安全协议分析

利用有色Petri网分析安全协议时存在空间爆炸问题,对此提出了构建入侵者成功攻击安全协议所需知识集RI与入侵者可以获得的知识集KI,并定义入侵成功函数的改进型有色Petri网。利用改进型有色Petri网对具体的Helsinki协议和TMN协议进行了分析。实验表明,该方法能大大简化带有入侵者的Petri网模型的构造过程,有效缓解了Petri网在分析安全协议时的空间爆炸问题。     

一种随机着色Petri网及模型的性能分析

针对随机Petri网（SPN）在系统性能分析时,其状态空间随着系统规模增大而指数性增长,造成求解稳定状态概率的复杂性的不足,提出了一种随机着色Petri网（SCPN）。分析了它的有界性和可达性,证明了它同构于一个一维连续时间的马尔可夫链;同时,也分析了随机着色Petri网用于建模和系统性能定量分析的方法。     

Algebraically structured colored Petri nets to model sequentialprocesses

Sequential processes can hardly be modeled with Colored Petri Nets (CPN). Their standard functions (such as "Succ" and "Prec") can only describe simple cases whereas modeling a complex sequence requires the definition of a function via a cumbersome and static table. In order to overcome these limitations, we first introduce a mixed structure based upon CPN and FIFO queues; then, we define an isomorphism between the set of colors and a finite field Z/pZ enabling symbolic calculation using polynomials associated with arcs instead of linear functions mapping sets into sets. Finally, several examples illustrate their modeling capabilities including failure recovery.     

Exploiting colored Petri nets to decide on permutation admissibility

In this work, we propose an innovative approach to investigate the admissibility of permutations to multistage interconnection networks—a challenging problem of switching theory. The proposed approach is centered upon modeling of multistage interconnection networks with colored Petri nets and use of Petri net analysis tools such as the unfolding technique and the invariants method. To assess the feasibility of the proposed approach we demonstrate that the complete unfoldings obtained in this work are polynomial in the problem size and employ an acyclic structure. The approach takes advantage of easy to use, yet extremely efficient, software tools.     

基于着色Petri网的联合反导作战系统建模

防空反导作战系统是一个复杂的军事系统,具有同步、并发、冲突等特点。应用着色Petri网技术对联合反TBM作战系统进行建模,符合联合反导作战系统的特点,能够有效地分析联合反导作战系统的静态结构和动态行为。分析了联合反导作战系统的信息交换关系,建立了系统的CPN模型,对模型进行了验证和仿真。     

A method of workflow scheduling based on colored Petri nets

Effective methods of workflow scheduling can improve the performance of workflow systems. Based on the study of existing scheduling methods, a method of workflow scheduling, called phased method, is proposed. This method is based on colored Petri nets. Activities of workflows are divided into several groups to be scheduled in different phases using this method. Details of the method are discussed. Experimental results show that the proposed method can deal with the uncertainties and the dynamic circumstances very well and a satisfactory balance can be achieved between static global optimization and dynamic local optimization.     

基于CPN的发布/订阅系统的建模及分析

提出了一种基于着色Petri网(CPN)的pub/sub系统协议分析方法.基于一种结构化P2P网络上的pub/sub系统协议,用着色Petri网对事件发布的消息处理进行建模和描述,并利用CPN tools对模型进行模拟仿真,通过对模型的可达图进行分析,表明了协议具有活性、可达性和有界性,验证了协议的可用性.     

Analyzing permutation capability of multistage interconnection networks with colored Petri nets

In a multistage interconnection network (MIN) the calculation of the number of permutations of the input terminals into the output terminals is a classic difficult problem. In this paper, we introduce an innovative technique based on Colored Petri Nets (known as CP-nets or CPNs) that will allow us to analyze the permutation capability of arbitrary MINs. We show how to verify whether a MIN is rearrangeable through the state space analysis of the associated CP-net and we measure the permutation capability of non-rearrangeable MINs in terms of the permutations that can be generated. The proposed approach takes advantage of powerful existing software tools, particularly, CPNTools, which is used to explore the occurrence graphs of CP-nets and determine the set of permutations performed by the modeled MINs. This new technique is easy to use and can be efficiently applied to MINs made of cross-bar switches.     

Modeling and generating context-aware agent-based applications with amended colored Petri nets

Context-awareness is become more crucial in mobile distributed computing systems. However, sophisticated modeling methods to analyze context-aware systems are still very few. Among those, the Colored Petri Net (CPN) is promising because it is proven to be useful for modeling system dynamics and concurrency control in more efficient ways. However, to support managing multiple configurations of components of context-aware applications, some features need to be added to specialize the CPNs. To address these challenges, our research has two idea: (a) to decompose a system into several meaningful subsystems, each of which we will call a pattern, and (b) to separate context from the patterns to realize context-pattern independence. Hence, we propose a modeling methodology to represent and analyze a context-aware agent-based system, which tends to be highly complex. We introduce CPNs as a method of capturing the dynamics of this contextual change. We define CPNs and a way to apply them in context-aware agent-based systems. We also describe a prototype system that we have developed called CPN Generator, which translates CPN specification into Java programs.     

基于CPN的程序测试用例生成方法的研究

采用成熟的建模仿真工具CPN tools不仅仅对程序设计语言的三种基本结构进行了建模,而且对并行程序中的并行结构也进行了建模和仿真。在不针对某些具体语言比如C语言的情况下,提出了生成测试用例的新方法,该方法对具备三种基本结构特性的所有程序都具有普遍适用性。对具有并行结构的程序通过化简寻找测试路径。最后在生成测试用例之后,又利用CPN tools对所获得的测试用例进行选择和评价,最终确定合适的测试用例,不仅能够保证获取的测试路径是完整的而且是最优的。     

Discrete-event simulation of fluid stochastic Petri nets

The purpose of this paper is to describe a method for the simulation of the recently introduced fluid stochastic Petri nets. Since such nets result in rather complex system of partial differential equations, numerical solution becomes a formidable task. Because of a mixed (discrete and continuous) state space, simulative solution also poses some interesting challenges, which are addressed in the paper     

基于CPN的列控系统等级转换建模与分析

在高速列车运行过程中,列控系统等级转换过程所用的时长和转换成功概率,直接影响列车运行安全和行车效率。利用有色Petri网对CTCS-3级列控系统和CTCS-2级列控系统之间等级转换以及典型设备故障导致降级场景分别建模,模拟等级转换过程中RBC（Radio Block Center,无线闭塞中心）,车载设备,有源应答器之间的信息交互过程。分析了列车速度对等级转换实时性的要求和对转换成功概率的影响,以及突发降级的可能性,结果表明建模方法满足CTCS-3级列控系统的安全性和兼容性要求。