Process Capability

 Cpk, CP, Ppk, Pp, Cpm, PPM

Process capability and performance indices tell us the amount of variation in an operation. The more the variation you have in a process the lower the capability of the process. The lower the capability, the higher the defect rate and cost.

You can use a process-capability study to assess the ability of a process to meet specifications.

During a quality improvement project, such as Six Sigma, a capability estimate is typically obtained at the start and end of the study to reflect the level of improvement that occurred.

Several capability estimates are in widespread use, including:

• C_p and C_pk are process capability estimates. They show how capable a process is of meeting its specification limits, used with continuous data.
• “Sigma” is a capability estimate typically used with attribute data (i.e., with defect rates).

Process Capability estimates like these essentially reflect the nonconformance rate of a process by expressing this performance in the form of a single number. Typically this involves calculating some ratio of the specification limits to process spread.

Which Index Is Right For Your Process?

Learn how to make process capability and control work for you.  Learn which process capability indices work for your processes.  We discuss long-term and short-term process indices. And, how to determine which apply to your process.

You will learn the difference between short-term and long-term indices. What indices apply to attribute data. You will learn the difference between process capability and process performance indices. And, when you should trust the numbers.

Hands-on Workshops

This is a "hands on" course.

Students will have workshops and perform capability calculations. Students should bring a statistical calculator. Loaners will be available if you don’t have one.

The Statistical Process Control (SPC) and the Production Part Approval Process (PPAP) guides are referenced in the class.  You don't have to be an automotive supplier to use these methods. They apply to and benefit all types of companies, especially companies involved in Six Sigma improvements.

Class content

You can have this class presented at your business for as little as $54.00 per person. Call us or click here to send a message. This class is 1 day and includes:

1.        Introduction and overview

2.        Process control vs. Process capability

3.        Understanding process capability

4.        Cp, Cpk, Pp, Ppk, CR, CR%, Cpl, Cpu & Cpm

5.        Process study assumptions and conditions

6.        Process improvement and control

7.        Workshops

8.        CEU and RU credits are awarded

Additional Resources

  Juran's Quality Handbook