I would say that an unilateral is indeed possible to calculate by using Cpk=CpU og Cpk=CpL depending on which side the tolerance is.
The issue must be that it will not reflect the direction of the distance, and it that sense it will not really evaluate the process:
Example:
Part #1 X1.0 Y0
Part #2 X-1.0 Y0
Part #3 X0 Y1.0
Part #4 X0 Y-1.0
Same distance from nominal will give a high (infinite) Cpk Value, but is the process stable?
Not really since the direction is different.
I am not sure if anyone can validate this one for me please:
Running PC-DMIS 2015.1 Operator Mode, exporting to Datapage+2012, does not export the XactMeasure True Position data to Datapage. However, PC-DMIS 2015.1 Online mode does.
