What is the Difference Between Process Capability and Process Performance?

Process capability and process performance are both useful indicators for determining the current performance of your organization. However, they are quite different in nature and a common problem among leaders is that they end up confusing them a great deal of the time in their analysis, leading to mistakes that can be easily avoided. It’s a good idea to familiarize yourself with the concept of both indicators, and to find out how they are related to your operations if you still have gaps in that area.

Short-Term vs. Long-Term

One of the biggest differences between the two factors is in their application in your planning stages. Normally, process capability can be a useful measurement for short-term analysis and improvements to your operations, while on the other hand, process performance can show you some useful details for the long-term development of the organization.

This will vary from one organization to another, and it’s not a universal measure. In some cases, long-term measurements simply make no sense in the context of your specific organization, and it’s important to align the knowledge obtained through performance measurements to this state adequately.

This difference mostly arises from the data used for calculating each factor, but we’ll cover that in more detail below. What’s important to understand is that you need data collection systems that can provide you with a good high-level overview of your whole operation, as well as the capability to sample your current variables on a smaller scale when appropriate.

Different Sample Sizes

You’re going to work with differently sized data sets when calculating your process capability and process performance. For measuring performance, you should typically use the full data set related to the process that is, all the data collected from start to finish, or however this scales in your current state.

On the other hand, when calculating process capability, you should use smaller samples that reflect the work done over a shorter period of time. This can allow you to make more localized measurements that give you a good overview of what exactly the limits of each process in your workflow are, and how close you are to reaching them.

High-Level Overview

Keep in mind that these are both parts of a statistical analysis methodology, and understanding their true use requires you to have a good overview of the way statistics are used in your organization at the moment. Many leaders still struggle with even the most fundamental concepts of statistical analysis, and you can’t realistically expect to get a good grasp of process capability, process performance, and other similar factors involved in analysis, if you don’t understand the general high-level methodology where they are used in the first place.

There are other factors that come in play at later stages as well, and you will need to know how to define the acceptability of a process, as well as know how to integrate new processes in your workflow without impacting the status of any of the current ones.

To this end, having a good understanding of process performance and capability can be of great benefit, and it can give you a strong push in trying to improve the statistical analysis practices in your organization. Just make sure you take things slowly and don’t attempt to take in too much at once if you’re feeling lost with the general concepts, as the differences between factors like these can sometimes take a while to click in your head.