Cp / Cpk Simulator
What is Cp/Cpk?
Monitoring the efficiency and performances of our manufacturing line is very important. It helps us find the unstable processes and improve them to increase our yield.
One important way to measure the performances is using Cp/Cpk.
Cp/Cpk are 2 statistical parameters that help us get a very good indicator of the stability and capability of our process.
In short, the main 2 ideas here is measuring the variation of our processes (the smaller the better) and how centered the processes are (How close the mean is to the center line between the upper and lower limits defined for each process).
Cp stands for Process Capability. A direct way to measure process capability. It measures how close your process is to the defined upper and lower limits of the process, compared to a reference optimal process. The larger the Cp index is , the less likely it is that any unit manufactured in your process will be outside the defined limits.
Cpk stands for Process Capability Index. It is the same as Cp but adjusted to measure process which is analysed with a non-centered distribution. Cpk measures how close you are to the optimal area of your process and how consistent your process is. The larger the Cpk index of your process is , the less likely it is that any unit manufactured in your process will be outside the defined limits.
How Cp, Cpk related to each other?
Your process perform with minimum variation, but it can be away from the optimal target towards one of the defined High or Low limit. This indicates a high index of Cp whereas Cpk will be low. On the other hand, your process may be on average exactly at the optimal target, but the variation level is high . In this scenario Cpk will also be lower, but Cp will be high. Cpk will be higher only when your process meets the optimal target consistently with minimum variation.