I've read numerous threads at this site related to inspection sampling and sampling plans, and I was unable to find an answer to the following question. I apologize if this question was previously asked and answered.

Question: When performing a sample lot inspection of 13 parts out of a lot of 79 and accepting on Zero defects, are the 13 parts to be inspected 100%, i.e. is every part feature / characteristic on the engineering drawing to be inspected?

Thank you

Hi Terry, 

 

In Advanced Product Quality Planning (APQP) that is used in Automotive and Aerospace, there is something referred to as Key Characteristics (KC). 

 

A Key Characteristic in Aerospace APQP is explained as follows - 
 

Quote

KC - An attribute or feature whose variation has a significant influence on product fit, performance, service life, or producibility; that requires specific action for the purpose of controlling variation

 

KCs for a part, subassembly, or system are those selected geometrical, material properties, functional, and/or cosmetic features; which are measurable, and whose variation control is necessary for fulfilling customer requirements and enhancing customer satisfaction.

 

Process KCs are those selected measurable characteristics of a process whose control is essential to manage the variation of part or system KCs.

 

 

The answer to your question is as follows - All Key Characteristics for the part/item need to be inspected. You need to check with the customer if they expect control over Process KCs as well. If the answer is yes, they may also need to be added to your inspection plan. 

 

Hope this helps. 

Thank you for the helpful information Vishwadeep

My question was driven by the fact that other quality folks in my organization believe that the "sample" lot of parts require 100% inspection of all part features. I was adamant that this logic made no sense. If you've performed a FAIR why would the Customer require additional parts to be inspected 100%. As to your input; the parts in question have no KC's or Critical features, which would further support my logic.