So what does this actually mean? Remember from the section on capability that a Cp value of 1 means that the total specified tolerance is just wide enough to contain the total process spread. A value of 2 means that process spread could fit into the specified tolerance twice, and a value of 3 means it could fit three times. This is shown graphically in the image below.
The Cp value of 1.43 for this process means that the process spread could fit comfortably within the specified tolerance, with a reasonable amount of 'elbow room', as shown below.
