A new measure of process capability, called process capability indicator and denoted by C1is proposed. It is of the form C1=deviation indicator (DI)+w×variation indicator (VI), where DI and VI, are, respectively, measures of the deviation of the process mean from the target value and the process variation, and both are relative to the tolerance. The weight factor w is used for deciding whether more emphasis should be put on VI (large w value) or on DI (small w value). Furthermore, by considering C1as a function of w, it has a spectrum of values which could provide more comprehensive comparison of different processes or measurement of the quality improvement of a process through several stages.