A Censored Cu‐sum Quality Control Scheme

Control of quality in the mail order and promotional distribution systems raises problems not easily handled by established techniques. Application of normal, batch based, charting and decision methods to the low levels of defects in continuing and variable flows of items is difficult. Cu‐sum methods are shown to have many advantages and offer both sensitivity and economy of operation. This article describes the development of a system for control of quality in a premium distribution organisation based on 100 per cent inspection by the customers and cu‐sum analysis of the returns