The Anatomy and Robustness of Discrete Proportional -Integral Adjustment and Its Application to Statistical Process Control

Abstract

This paper explains the nature and importance of Proportional-Integral control and shows how it may be adapted to Statistical Process Control. The relation of this type of control to exponential smoothing, minimum mean squared error control, and optimal constrained schemes is discussed. Robustness properties which simplify considerably the practical application of this type of control are demonstrated.