急件冲击下关键设备生产缓冲的GERT模型  

A GERT Model for Calculating the Production Buffering of Critical Equipment with Urgent Jobs Considered

作　　者：刘远[1] 郝晶晶[1,2] 应洪斌[1] 

机构地区：[1]浙江师范大学经济与管理学院,浙江金华321004 [2]南京航空航天大学经济与管理学院,江苏南京211106

出　　处：《工业工程》2014年第2期23-30,共8页Industrial Engineering Journal

基　　金：国家自然科学基金资助项目(71301149;71203199);教育部人文社会科学研究青年项目(13YJC630103);浙江省自然科学基金青年基金项目(LQ12G02002;LQ13G010006);杭州电子科技大学浙江省高校人文社科重点研究基地资助(ZD03-2013ZB1)

摘　　要：为了降低非预期生产急件对关键设备正常生产活动的冲击,保证生产计划的稳定性,研究了关键设备的应急生产缓冲设计问题,为生产管理者合理地确定预留产能提供了理论依据。结合排队理论,分析了生产急件到达和处理活动,证明其属于一类负指数随机过程,揭示了生产状态的动态转移规律和实现条件;将关键设备组的急件加工过程描述为一类GERT(graphic evaluation and review technology)模型,测算状态转移过程的状态转移参数和矩母函数;结合梅森公式,设计系统状态稳态概率的求解方法,分析关键设备生产缓冲与稳态概率之间的关系,探寻其定量化表征。通过某研究院加工中心设备组的案例研究,发现关键设备组因急件冲突导致月生产计划变更的情况平均降低14.6%,较好地控制生产计划与调度工作的不良波动,从而验证了模型和方法的可行性和适用性。In order to reduce the negative fluctuation of unexpected urgent jobs on the normal production of critical equipment and assure the consistency of production schedule, a novel method for determining the production buffering of critical equipment in a manufacturing system containing unexpected urgent jobs is developed. The production manager can confirm the proper reserved capabilities according to the research result. Specifically, the procedures of urgent job arrival and manufacturing are discussed based on the queuing theory with a negative exponential distribution, and the transferring rules and realistic conditions are revealed. Additionally, a kind of graphic evaluation and review technology （GERT） model is utilized to describe tile operation of urgent jobs in critical equipment and the transfer between adjacent nodes is studied. In doing so, the node transferring parameters and the moment generating functions are calculated. Furthermore, by the Mason rule, the probabilities of the stable states are determined to provide support for obtaining the buffering capacity of critical equipment. Finally, a group of machining centers in a research institution is used as a case study. It is shown that the average reduction of adjusted situations of monthly production plan of critical equipment group reaches to 14.6%. Thus, the fluctuation of production sched- ule can be effectively controlled and the feasibility and practicality of the proposed method are verified.

关 键 词：生产缓冲 生产急件 关键设备 GERT模型 

分 类 号：F273[经济管理—企业管理] TP273[经济管理—国民经济]