为研究机器故障和维修活动对制造过程性能的影响,提出一种基于广义随机Petri网的制造过程建模与性能分析方法。分析了随机机器故障特征;定义了两种故障发现模式和两种中断作业处理策略;给出具有随机机器故障的制造过程的不同模型方法;通过对模型结构特征的分析,证明了其有效性。针对不同策略和参数设置进行了性能仿真。分别以平均产量和平均过程流时间等性能指标,分析了单个工作站的性能;采用平均产量,分析了具有两个工作站的流水线的性能。仿真结果表明,故障率、平均维修时间、缓存数量配置、维修工人数量、故障发现模式和中断作业处理策略是影响具有随机机器故障的制造过程性能的主要因素。
To study the influence on the performance of manufacturing processes exerted by the machine failures and repairing activities, an approach based on Generalized Stochastic Petri Net (GSPN)was proposed for manufacturing processes' modeling and performance analysis. The characteristics of stochastic machine failures were analyzed. Two failure-detection modes and two interrupted job-handling policies were defined respectively. Different models for manufacturing processes which were subject to stochastic failures were presented. Validity of the models was verified by analyzing the structural characteristics. Simulation were performed to deal with different policies and parameter configurations. Performance of single work station was analyzed by the average throughput and the mean process flow time. Performance of the flow line with two work stations was analyzed by average throughput. Simulation re- sults demonstrated that the failure rate, the mean time to repair, the number of buffers, the number of repair personnel, failure-detection modes and interrupted-job-handling policies were the main influencing factors for manufacturing processes' performance.