时间Petri网在项目进度管理建模中的应用

通过分析现有时延Petri网和时间Petri网在项目进度管理仿真模型的不足,提出基于库所时间约束Petri网的项目进度管理模型,该模型具备全局时钟特性,不仅能体现工序自身时间参数,同时能对外部资源等工序外延时间约束进行建模。实例仿真结果表明该模型的有效性。     

Reachability analysis of logic Petri nets using incidence matrix

Logic Petri nets (LPNs) can simplify the net-structure and mitigate the problem of state space explosion. To directly investigate the properties of LPNs, a new analysis method of LPNs is introduced in this paper based on incidence matrix. The enabled conditions of transitions are given, and reachable markings are calculated based on the constructed incidence matrix of LPNs. The state equation of LPNs is defined, and the reachability of LPNs is analysed. Compared with the previous work, the incidence matrix in this paper can contain more information and describes the logic expressions and arcs of LPNs. The computational complexity of LPNs is lower. Finally, the validity, reliability and effectiveness of the proposed method are illustrated by analysing an actual case. The theoretical and practical values of LPNs are enhanced.     

基于时间Petri网的物流系统建模与仿真实例

介绍一种使用时间Petri网对物流系统进行建模的方法。Petri网对带有并发性、异步性、分布式和非确定性的系统具有较强的描述能力。但在以往对物流系统的建模中,一般都采用原始Petri网,未考虑时间因素,因而只是从逻辑层面上描述物流系统,而缺少对系统的时间特性描述。选用时间Petri网对物流系统进行建模,模型能更加符合实际情况。实例和仿真结果验证了该方法的有效性。     

基于Petri网的母鸡转舍业务流程建模优化研究

选择农牧养殖业中的母鸡转舍这一业务流程建立Petri网模型,并对模型进行分析计算,找出时间瓶颈,依据ECRS原则提出优化方案,利用流程周期时间指标评价优化前后流程的效率,比较表明该模型在农牧养殖业务流程优化中是非常有效的。     

基于GSPN的物资采购流程效率分析模型

物资采购流程的再造即采购流程BPR可以有效提高供应链整体竞争力,而对采购流程的运作效率和性能的分析是BPR的基础和前提,也是当前BPR研究的热点。本文首先给出了广义随机Petri网(GSPN)的定义和相关性能评价与分析的方法,然后根据物资采购流程的实际特点,建立了基于GSPN的效率分析模型。     

基于Petri网的化学危险品出入库流程的建模与仿真

化学危险品出入库的安全性是其物流管理的一个重要内容,利用Petri网对化学危险品出入库流程进行了建模,并运用ExSpect软件对模型进行仿真分析,针对分析结果提出了一些安全防范措施,提升了化学危险品出入的安全高效性。     

Extension of specification language for soundness and completeness of service workflow

A Service Workflow is an aggregation of distributed services to fulfill specific functionalities. With ever increasing available services, the methodologies for the selections of the services against the given requirements become main research subjects in multiple disciplines. A few of researchers have contributed to the formal specification languages and the methods for model checking; however, existing methods have the difficulties to tackle with the complexity of workflow compositions. In this paper, we propose to formalize the specification language to reduce the complexity of the workflow composition. To this end, we extend a specification language with the consideration of formal logic, so that some effective theorems can be derived for the verification of syntax, semantics, and inference rules in the workflow composition. The logic-based approach automates compliance checking effectively. The Service Workflow Specification (SWSpec) has been extended and formulated, and the soundness, completeness, and consistency of SWSpec applications have been verified; note that a logic-based SWSpec is mandatory for the development of model checking. The application of the proposed SWSpec has been demonstrated by the examples with the addressed soundness, completeness, and consistency.