Non-Conformance Costs in Turbogenerators

This is a vague, broad, ambiguous topic (other adjectives if you like may be added)

The non conformances as a rule are classified into a few broad categories

a) Performance related

b) Efficiency related

c) Product design related

d) Process design related

e) Unstructured

For the user, the nonconformance is in first two and rerely in the last one of the five types.

For the mfr they fall in all the categories.

For NC analysis the first aspect is who you are manufacturer or the user.

If you are a user then the question you ask is what you expect from the equipment (spelt out or some times unspelt)- When the equipment characteristics do not meet this it is nonconformance.

If you are a manufacturer, the problem is slightly more acute - you have to extrapolate the non-conformance to the main equipment and then decide on this.

The second portion (I assume you mean where the nonconformance report is raised ?) is the criticality/ severity of the nonconformance

Does it affect the equipment performance, safety, statutory requirements ?

Mildly compromises these ?

Might affect these under severe circumstances- not likely to happen but may ?

Does not affect it at all ?

Based on all the above parameters you decide whether to raise it or not.

Taking an example,

Say Rotor Journal is made Under size-

Now the effect is on operation ? yes unless you change the bearing, yes if the size is so much that it compromises strength or the surface velocity and hence film formation) else no.

Do you report it even if it is no ? It depends on your procedures (assuming you are manufacturer)- though it looks it does not affect the customer, but it does (in case of replacement of the bearings) - so you must record as reportable. But assume the minimum bearing like is 15 years - then most likely it will be non reportable.

It is difficult to spell out the actual procedure however the broad guide lines are as above. Total procedure has to be formed at your end based on your interpretation of the processes and equipment (product).

You may study certain concepts like CTQ (Critical to Quality) Parameters, Identification of CTQ, CTQ Tree, QFD etc , they are usually a bit complex.