Аннотация:Summary Statistical control schemes are widely used in industry for monitoring the quality of manufactured products. These schemes provide statistically motivated criteria for detecting deviations in behavior of incoming data from some expected or desirable patterns. The present work considers some theoretical and graphical aspects of control charting and relations between this area and the field of engineering process control. The emphasis of the paper is on the Cusum technique and its relation to other statistical tools, such as the Exponentially Weighted Moving Average (EWMA). Also discussed are generalizations of this technique that enable one to incorporate concomitant information in the decision making process, as well as introduce weights which not only enhance the statistical performance of a Cusum chart with respect to drifts in the process mean, but also lead to a type of chart suitable for the purpose of multivariate statistical process control. Use of the discussed techniques is illustrated by means of several examples.
