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。     

基于分层模糊有色Petri网的防空C~3I系统建模研究

通过分析某防空C~3I系统的组成和运行方式,针对系统结构复杂、多种资源、资源多种模糊属性等特点,定义了一种分层模糊有色Petri网HFCPN,并给出具体的推理算法。在此基础上建立该防空C~3I系统模型,从而提出了一种建立防空C~3I系统分析模型的新方法。最后通过应用实例验证了该方法在描述系统分布、并发、异步等特性的同时,分析系统资源多种模糊属性问题的能力。     

基于Petri网的流程挖掘算法设计与应用

讨论了利用Petri网对应用系统日志进行建模和分析的方法,给出一个日志过滤、简化及转换模型的方法,提出了一个基于Petri网的专家挖掘算法,其中专家是指对某个业务流程特别熟练的人.以广州地铁法律咨询流程为例,介绍了该流程的建模和模型的简化算法.使用该算法可以有效的对操作人员进行评估和考核,有利于资源的合理配置.最后,以法律咨询流程日志为基础进行了实验,实验结果表明,算法认准率达90%以上,且通过模型简化可有效减低算法时间复杂度.     

着色Petri网在科技计划项目管理系统建模中的应用

在深入研究科技计划项目管理业务基础上,鉴于Petri网的特点,提出了利用着色Petri网建模科技计划项目管理系统的方法.分析了着色Petri网适合于系统建模的原因,以项目管理评审环节为例讨论了着色Petri网在建模中的应用,并建立了基于着色Petri网的系统模型.通过对该模型的分析仿真结果表明,该方法是可行和有效的.     

可编程逻辑控制器的平行Petri网设计与实现方法

为了实现可编程逻辑控制器(PLC)的形式化设计, 定义了一种可以感知和执行的新型Petri网, 称为平行Petri 网. 将输入输出变量映射到库所结点上, 描述了PLC的Petri网模型的一般设计方法, 进而给出了其动态演化算法. 通 过C语言和TwinCAT联合编程, 使得Petri网与被控物理对象平行演化, 实现了Petri网对物理过程的平行感知和控制, 并完成了实验验证. 该方法可以缩短控制代码的开发周期, 简化程序复用的复杂性, 为平行系统在PLC工程中的应 用提供了有效工具.     

Minimizing cycle time and group scheduling, using Petri nets a study of heuristic methods

The objective of this paper is a study of minimizing the maximum completion time min F _max, or cycle time of the last job of a given family of jobs using flow shop heuristic scheduling techniques. Three methods are presented: minimize idle time (MIT); Campbell, Dudek and Smith (CDS); and Palmer. An example problem with ten jobs and five machines is used to compare results of these methods. A deterministic t-timed colored Petri net model has been developed for scheduling problem. An execution of the deterministic timed Petri net allows to compute performance measures by applying graph traversing algorithms starting from initial global state and going into a desirable final state(s) of the production system. The objective of the job scheduling policy is minimizing the cycle time of the last job scheduled in the pipeline of a given family of jobs. Three heuristic scheduling methods have been implemented. First, a sub-optimal sequence of jobs to be scheduled is generated. Second, a Petri net-based simulator with graphical user interface to monitor execution of the sequence of tasks on machines is dynamically designed. A deterministic t-timed colored Petri net model has been developed and implemented for flexible manufacturing systems (FMS). An execution of the deterministic timed Petri net into a reachability graph allows to compute performance measures by applying graph traversing algorithms starting from initial global state to a desirable final state(s) of the production system.     

Modelling of an interactive system with an agent-based architecture using Petri nets, application of the method to the supervision of a transport system

This article presents an original method using high level Petri nets for the specification and design of interactive systems. We suggest an agent oriented architecture based on the classic components of an interactive application (application, dialogue control, interface with the application). Our approach is validated via the specification and design of a human–machine interface used in the supervision of a land-based transport system (bus/tramway).