C_p 1 indicates that if the process average can be centered,then more than 99.73% of the observations will fall inside the specification limits.

Question

C_p >1 indicates that if the process average can be centered,then more than 99.73% of the observations will fall inside the specification limits.

Quizplus · Accepted Answer

A process that is centered and has a standard deviation of 1 (as indicated by the "1" in the first component of the process capability index) will have 99.73% of observations falling within the specification limits. This is because 99.73% of observations fall within 3 standard deviations of the mean in a normal distribution, and with a standard deviation of 1, this means the specification limits are 6 standard deviations apart, giving a tolerance of 6 times the standard deviation for the process to operate within.

Cp >1 Indicates That If the Process Average Can

C_p >1 Indicates That If the Process Average Can