1. When can tight specifications not lead to a quality product?
When the quality system doesn't include Measurement Systems Analyses (MSAs).
Most quality systems include annual Calibrations, but this only tells whether the gage is on target. Another important aspect is how repeatable the gage is if you read the same part over & over again.
A MSA is designed to determine the gage's measurement error - will multiple measurements on the same part results in  values within +/- 5 or +/- 0.5.
Come be a part of a discussion on improving gage reliability. Topics to be covered include:
Case study on when tight specifications didn't lead to quality results.
The value of performing both Calibrations & MSAs.
How to deal with gages that aren't traceable back to a common standard (e.g. NIST).