Q: Our company, certified to ISO 9001:2008 Quality management systems–Requirements, is experiencing quite a bit of supplier non-conformance.
An option we are interested in is to have a set of manufacturing drawings for our suppliers and a set of inspection drawings. Either the manufacturing set would require tighter tolerance than the inspection set, or the inspection set would have looser tolerances than the manufacturing set.
What would the criteria be to introduce this theory into our procedures?
A: I suggest that you consider the point of ISO 9001:2008 Quality management systems–Requirements, clause 7.1, regarding the development of product objectives. Your planned approach is similar to what is intended by this clause.
The organization should set its product requirements during the product planning stage. Product requirements should be based upon design inputs, outputs, verifications and validations. This provides the essential measurements (tolerances) required for the product to function as designed or intended.
The requirements sent to suppliers, or to the shop floor, should be within the design tolerances or criteria, but not necessarily the same. However, in the event that inspection or a supplier identifies/provides a product that is outside the drawing requirements, it would be up to the engineer or the designer to decide if the product still meets the design criteria. If so, the product would be disposition “accept as is” and would still function as planned.
If repetitious non-conformance is encountered and the product is still within the design criteria, then changes to the supplier and inspection criteria should be considered to prevent continued non-conformance. If the non-conformance does not meet the product requirement or the design criteria, corrective action should be taken with the supplier.
ASQ Senior Member
Managing Director of Aston Technical Consulting Services