scope:

Purpose and Scope

This document is Annex 4 of NASA-HDBK-8730.19 [40]. It provides guidelines for computing metrics by which conformance testing for test and calibration processes can be evaluated. Chief among these metrics are measurement decision risks. These include the risk of incorrectly accepting a nonconforming equipment attribute and the risk of incorrectly rejecting a conforming attribute. The former is called False Accept Risk and the latter is termed False Reject Risk. A principal objective of this Annex is to accumulate and focus the body of knowledge of measurement decision risk to provide uniform guidance in the application of this knowledge to estimate and manage such risk, particularly as it relates to NASA tests and calibrations.

In addition to providing guidelines for estimating and managing measurement decision risks, this Annex addresses the evaluation of these risks in terms of their impact on both operating costs and on the cost of the undesirable consequences of incorrect test decisions. Further, the guidelines provided herein can be applied to equipment and system design issues involving decisions regarding accuracy requirements and available support capability.

The principles and methods presented in this Annex are applicable to any conformance test that relies on measured values to provide information on which to base acceptance or rejection decisions.