质量和成本约束下CSP-T和Spk集成过程控制方案

多水平连续抽样检验方案(CSP-T)是在线过程质量控制工具,但该方案的第一类风险和第二类风险都较高,且不能满足成本约束。提出了CSP-T和过程良率指数(Spk)集成过程控制方案,该集成方案在满足质量约束的同时,以最小成本运行,并将两类风险控制在既定水平。建立了极限检验能力下的最优CSP-T方案,依据数据的计数特征驱动质量控制方案运行。基于Spk估计的精确分布建立了风险控制方案,依据数据的计量特征驱动风险控制方案运行。质量控制方案和风险控制方案是独立互补关系。相比于CSP-T方案,检验工作量没有增加。企业案例验证了集成控制方案的可行性和有效性。

An Integrating Control Scheme of CSP-T and Spk under the Quality and Cost Constraints

Multiple level continuous sampling plan (CSP-T) is an on-line process quality control tool. The type I risk and type II risk are both high and the cost constraint cannot be satisfied in CSP-T. An integrating control scheme between CSP-T and S_pk is proposed, which can meet quality constraint, being carried out with the least cost and controlling the two types of risk at the given level. The optimal CSP-T plan, driven by the attribute characteristics of the sample, is constructed under the quality and cost constraints. The risk control scheme is presented based on the accurate distribution of the estimation of the process yield index (S_pk). The two types of risk can be controlled at the given levels for the stipulated quality and cost constraints. The quality control scheme and the risk control scheme work independently and complementarily. The inspection workload is not increased compared with the traditional CSP-T plan. The feasibility and effectiveness of the proposed scheme are verified by an enterprise case.