带有暂停检查的调整型抽样系统的复合特性

COMPOSITE OPERATING CHARACTPRISTICS OF SAMPLING SYSTEMS WITH RULES OF SEVERITY ADJUSTMENT AND DISCONTINUING INSPECTION

分析由正常检查、加严检查和放宽检查组成的三个抽样方案及其转移规则和暂停检查规则所构成的调整型抽样系统的复合特性,关键在于寻找在各单个抽样方案之不期望检查的批的比率表达式。解决这一问题的传统方法是Markov链法或计算机模拟法。本文以不同于上述传统方法的一元母函数方法,研究了带有暂停检查的调整型抽样系统的复合特性。导出了当暂停检查可以转移到其它检查状态时整个抽样系统处于正常检查、加严检查和放宽检查的期望比率和,进而得出了复合OC函数和期望抽检样本量E(x)的表达式,并讨论了它们在计量抽样检查中的应用。

The key to the analysis of the composite operating characteristics of sampling systems having normal, tightened, and reduced plans together with an entire switching procedure involving the discontinuing inspection lies in finding out the expected proportions of the lots inspected under the various plans. Traditional means employed in such cases are the methods of Markov chain or computer simulation. In this paper, an expression of the expected proportion of lots inspected under various plans is developed, using the method of uni-variable generating function, a departure from the traditional methods mentioned above, As the discontinuing inspection can be switched to other objects of inspection, the composite operating characteristics of sampling system are studied with rules of severity adjustment and discontinuing inspection. Formulae for the composité OC function p_(ac) and the expected mean sample sizes inspected E(n)are instroduced herein. Application of these results to the case of sampling for inspection by variables are discussed. The calculation of P_(ac) and E(n) of sampling systems by variables with severity adjustment such as ISO 3951, ANSI-Z-1.9, BS 6002 and DSO 5-30/1 systems, are completely solved. All results can be transferred parallelly to the approximate calculation of P_(ac) and E(n) of sampling inspection by attributes,