Based On Requirement
Hi,
here we go,
The variable & attribute have their own advantages & disadvantages.
Based on the customer requirement & drawing spec you need to decide.
When ever a customer asks for a Cp/Cpk result he will be expecting a variable study report & you have no other go you need to go for an Varibale type of inspection. It's not that with a attribute type of measurement we won't get the Cp/Cpk. As James rightly said its based on the application and also the customer requirement & also the attribute type of inspection is fast when compared to variable type of inspection.
The variable type of inspection requires more skill & knowledge to read.
And the data got thru variable type of study helps you in taking good & right decision @ right times.
shesha