传统的设备采购系统不能随外界环境的变化而进行相应的重组。为此，本文提出了一种基于面向对象Petri网的设备采购系统的工作流模型。该模型将各个对象的内部结构进行封装，避免了相互之间的库所与变迁的定义干涉。模型具有模块化、图形化、结构化的特性，提高了设备采购系统的可重用性和可扩展性。以审批部门的OOPN模型为例，求其关联矩阵、可覆盖性树和P不变量，并进行相关性分析，证明了构建的模型具有良好的性能并满足系统变化和重组的要求。

The Traditional equipment purchasing system can not be reorganized according to the changes of external environment, so a workflowing model of equipment procurement system which is based on objectoriented Petri Nets is proposed. This model can package the internal structure of each object to avoid the mutual definition interference between places and transitions． It also has the characteristics of modularization，graphization and structurization, which improves the reusability and extendibility of the equipment purchasing system. Taking an example of the OOPN model of the examination and approval department, its incidence matrix, coverability tree and the Pinvariant are figured out and their relativities are analyzed, which proves that the constructed model has good performance and satisfies the requirement of the system changes and reorganization.