Cpk Index Calculator

Calculate Cpk Index (Cpk)







Formula

The formula to calculate the Cpk Index (Cpk) is:

\[ Cpk = \min\left(\frac{USL - \mu}{3\sigma}, \frac{\mu - LSL}{3\sigma}\right) \]

Where:

Definition

Example

Let's say the upper specification limit (USL) is 10, the process mean (μ) is 7, the process standard deviation (σ) is 1, and the lower specification limit (LSL) is 4. Using the formula:

\[ Cpk = \min\left(\frac{10 - 7}{3 \times 1}, \frac{7 - 4}{3 \times 1}\right) = \min\left(\frac{3}{3}, \frac{3}{3}\right) = 1 \]

So, the Cpk Index is 1.

Extended information about "Cpk-Index-Calculator"

How to Calculate Cp and Cpk

Formula: \( Cp = \frac{USL - LSL}{6\sigma} \)

Example: \( Cp = \frac{10 - 2}{6 \times 0.5} \)

How is Cpk Calculated

Formula: \( Cpk = \min \left( \frac{USL - \mu}{3\sigma}, \frac{\mu - LSL}{3\sigma} \right) \)

Example: \( Cpk = \min \left( \frac{10 - 6}{3 \times 0.5}, \frac{6 - 2}{3 \times 0.5} \right) \)

Calculating Cp and Cpk

Formula: \( Cp = \frac{USL - LSL}{6\sigma} \) and \( Cpk = \min \left( \frac{USL - \mu}{3\sigma}, \frac{\mu - LSL}{3\sigma} \right) \)

Example: \( Cp = \frac{12 - 4}{6 \times 0.6} \) and \( Cpk = \min \left( \frac{12 - 8}{3 \times 0.6}, \frac{8 - 4}{3 \times 0.6} \right) \)

Formula to Calculate Cpk

Formula: \( Cpk = \min \left( \frac{USL - \mu}{3\sigma}, \frac{\mu - LSL}{3\sigma} \right) \)

Example: \( Cpk = \min \left( \frac{15 - 10}{3 \times 0.7}, \frac{10 - 5}{3 \times 0.7} \right) \)