In Geometric Dimensioning and Tolerancing (GD&T) there has been a long-standing conflict between the worlds of specification and measurement. The goal of specification is to ensure that components will function; the goal of measurement is to ensure that manufactured components meet those functional requirements. 

Typical answers include: cheaper, faster, most accurate, none of which would pass a technical smell test. On reflection, many might say they want calibration to tell them if the item to be calibrated is any good or not while not defining what ‘good’ means from a technical point of view.

A number of measurement devices come equipped with internal or user calibration functions. Allowing the user to calibrate their measurement equipment on a more frequent basis gives greater control over the quality process; however, with great control comes great responsibility. 

Internal Quality Audits are a requirement of ISO 9001 that rarely bring value to an organization past simply maintaining compliance to the standard. Despite their best efforts, even well-trained internal auditors may not be as effective as they could be.