What Does CP 1.33 Mean?

What does a Cpk of 1.67 mean?

The Capability Index, Cpk.

The outcome of a Process Capability study is a single metric, which provides an indication of the ability of a process to consistently provide output which is within required specifications.

CPK <1.00 (Poor, incapable) 1.00< CPK <1.67 (Fair) CPK >1.67 (Excellent, Capable).

What is a good Cp and Cpk value?

We generally want a Cpk of at least 1.33 [4 sigma] or higher to satisfy most customers. Cpk can have an upper and lower value reported. If the upper value is 2 and the lower is 1, we say it has been shifted to the left.

What does a Cp of 1.5 mean?

A Cp of less than one indicates that the process spread is greater than the specification. This means that some of the data lies outside the specification. … So a Cp of 1.5 means the process can fit inside the specification 1.5 times. A Cp greater than one is obviously desirable.

How many Sigma is 1.67 Cpk?

6 sigmaCp = Cpk = 1.67. The sigma level is now 5 – the specifications are five standard deviations away from the average. The out of specification has decreased to 0.57 ppm. The fourth curve represents that magical 6 sigma level.

What if CP is higher than CPK?

So this is how Cp and Cpk work together: When the values are similar, the mean is close to the middle of the specification limits. When Cp is greater than Cpk, the mean is nearer to one specification limit or the other.

What is K in CPK?

In the Cpk, k stands for off-target variation. K= (Process Centre-Process Mean)/50%of USL-LSL and if we talk about process center; Process center = (USL+LSL)/2, and the process mean is the average or mean of the process data points.

What is CP in manufacturing?

Share This. A measure of process capability, calculated as a ratio of tolerance or specification limits (upper limit – lower limit) divided by the process variation (6 standard deviations).

What is the maximum value of CP and CPK?

The minimum value of “k” is 0 and the maximum is 1.0. A perfectly centered process will have Cp = Cpk. Both Cpk and Ppk relate the standard deviation and centering of the process about the midpoint to the allowable tolerance specifications.

How is CP calculated?

Stats. The CP (“combat power”) is calculated based off the Pokémon species’ base values, the power up level, and three hidden numbers called “IVs” (individual values.) … The higher your Trainer Level is, the more you can power up a Pokémon.

What is a good CP value?

By convention, when a process has a Cp value less than 1.0, it is considered potentially incapable of meeting specification requirements. Conversely, when a process Cp is greater than or equal to 1.0, the process has the potential of being capable. Ideally, the Cp should be as high as possible.

What is CP CPK?

Cp and Cpk, commonly referred to as process capability indices, are used to define the ability of a process to produce a product that meets requirements. … Specifications are normally defined in terms of nominal (+/-) tolerances or ranges (low to high.

Can CP CPK be negative?

Both Cpk and Ppk can be a negative numbers. It means that, on average, the process is not meeting customer requirements.

What is CP SPC?

Capability (Cp) and performance (Cpk) charts illustrate a process’s ability to meet specifications. Although SPC control charts can reveal whether a process is stable, they do not indicate whether the process is capable of producing acceptable output—and whether it is performing to capability.

What does CP value mean?

Cp is a ratio of the specification spread to the process spread. The process spread is often defined as the 6-sigma spread of the process (that is, 6 times the within-subgroup standard deviation). Higher Cp values indicate a more capable process. … When the specification spread is less than the process spread, Cp is low.

What is CP Six Sigma?

Cp measures the capability of a process to meet its specification limits. It is the ratio between the required and actual variability. More mathematically, the Cp is the ratio of the Spec difference (upper – lower) divided by 6-sigma, which is the spread of a normal curve.