Abstract
Assessment of process health is an important aspect of any quality system. While control charts are often used in the day-to-day operations of processes, it is also helpful to take a retrospective look at past performance in the form of an overall process health assessment to identify specific opportunities for future improvement efforts. In this paper, we recommend a complete set of indices to evaluate various aspects of process health including actual process performance, process stability, process centering, and potential process capability. We show how the set of indices can be particularly useful when there are many processes to evaluate simultaneously. Both tabular and graphical methods using these indices will be shown for quick identification of potential problem areas that warrant more investigation. We also demonstrate how these metrics can be used when there are both two-sided and one-sided specifications (with and without a defined target). Finally, we explore the connection between the process and measurement system and recommend indices for evaluating the health of the measurement system.