Thoughts on Measuring NDE Effectiveness

You know those balls that they put on car antennas so you can find them in the parking lot?
Those should be on EVERY CAR!  – Homer J. Simpson

(An inspection system that “finds” everything isn’t very useful. But it won’t miss anything.)

Thoughts … with a tip of the hat to Derek Sturges.

 
Think of an NDE process you know:

What size defect is it capable of detecting?
(How do you know that?)

What proportion of those defects is detected?
(How do you know that?)

Consider two NDE inspectors you have:

Do they both perform equally well?
(How do you know that?)

Does their performance meet your requirements?
(How do you know that?)

Compare two NDE processes:

Which process finds the smallest defects?
(How do you know that?)

Which process finds the most defects?
(How do you know that?)

Your company makes industrial products:

Would a better inspection improve product life?
… or would the effort be wasted?
(How do you know that?)

When should you schedule an in-service inspection?
(How do you know that?)

Remember: It isn’t the smallest crack you can find that’s important
– it’s the largest one you can miss. How do you know what that size is?