Precision measures for processes with multiple manufacturing lines

Abstract

Process capability indices C-p, and C-pk have been popularly used in the manufacturing industry for providing measures of process potential and performance. The precision index C-p is used to measure product quality consistency, while the yield index C-pk is used to provide measures of percentage of product conforming to manufacturing specifications. Properties of C-p for processes with a single manufacturing line have been investigated extensively. However, research on properties of C-p for processes with multiple manufacturing lines have been neglected. In this paper, we consider the precision index C-p for processes with three manufacturing lines. We develop a practical procedure for process precision testing to determine whether a process meets the precision requirement preset in the factory. An application example is given.