Process Capability Definition

Process capability
Introduction
Process capability Process capability represents the performance of a process in a state of statistical control and is determined by the total variability that exists because of all common causes present in the system. The process capability is a measurable property of a process to the specification, expressed as a process capability index (e.g., Cpk or Cpm) or as a process performance index (e.g., Ppk or Ppm)
It can also be viewed as the variation in the product quality characteristic that remains after all special causes are removed.
Two parts of process capability are: 1) measure the variability of the output of a process, and 2) compare that variability with a proposed specification or product tolerance.

Without knowing it, their weak commitment is likely to lead indirectly to the fact that insufficient resources, if any at all, are allocated to implement and conduct process capability studies. The lack of appropriate resources directly results in a shortage of knowledge about how to conduct process capability studies among all co‐workers. Even if all theoretical aspects of how process capability studies should be conducted sometimes are known within the organisation, the final method used is often too simplified. One possible explanation for these simplifications is that the lack of resources forces the organisation to find the cheapest possible way to proceed, without reflecting on how it influences the results. The relatively poor knowledge about the theoretical aspects among co‐workers, combined with managers’ preoccupation with solving other day‐to‐day problems, makes it hard for everyone within the organisation to realise the advantages of conducting process capability studies

Obviously this method requires that members of the organisation are used to measure different characteristics. However, in some organisations, there are no such things as gauges, and if they exist, they are often inadequately calibrated. Another barrier when conducting process capability studies is the high speed of modern production. In some operations there is simply no time left to perform measurements, which enhance the importance of capable processes. Another aspect of this problem is that important characteristics are sometimes hard to measure and control. This problem has special significance within process industries, where important characteristics may be almost impossible to measure for to practical