着色时间工作流网任务调度的时间约束分析

为实现工作流管理系统中的任务调度和时间管理，避免流程在多任务运转时产生溢出，提高流程的工作效率。采用不固定时延定义了着色时间Petri网，通过控制任务间的最小时距避免了溢出，并用任务监测器实现了相应的控制策略。以各任务间的时间间隔最小为优化目标，对串行、并行、条件选择和循环四种基本着色时间工作流网进行了时序分析和任务调度，推导出多任务在基本着色时间工作流网调度的数学模型和着色时间工作流网整体运行时间函数的计算公式。最后通过一个审批流程对论述的任务调度方法进行了验证。

Time Constraints Analysis of Task Scheduling for Colored Timed Workflow Net

To realize task scheduling and time management of workflow management system,avoid overflow while multitasks running in the workflow at the same time,and improve workflow's efficiency,floating-delay is adopted to define colored timed Petri net.Overflows are avoided through controlling minimum time lags between tasks.Corresponding control strategies are implemented by the use of task monitor.Optimization aiming is the interval between each task is minimum.Temporal analysis and task scheduling are implemented for basic colored timed workflow nets,namely serial,parallel,conditional option and loop colored timed workflow net.Mathematic models of multitasks scheduling for basic colored timed workflow net are presented,and the formulae of calculating the whole workflows running time are given.At last an examine and approve workflow model built upon Colored timed Petri net is illustrated as an example to analyze and validate the methods discussed on multitasks scheduling.