Process attribute rating and sensitivity analysis in process assessment

Abstract

The capability level of a process assessed on the basis of International Standard ISO/IEC 15504 is determined by utilizing process attributes ratings (PAs). PA rating as a composite indicator is determined by the extent to which outcomes or the implemented practices are achieved. However, the ISO/IEC 15504 standards do not provide recommendations as to assessment methods, including the following: (i) which of the outcomes or practices implemented are evaluated as an intermediate step in rating the PA; and (ii) how a set of their achievements is aggregated into the PA rating. This study addresses a simple additive weighting method based on the performance value and weights of practices implemented as well as its rationale, in order to facilitate consistent and repeatable PA ratings. Then, sensitivity analysis is conducted to evaluate how much a change in the weight or performance value of an implemented practice will affect and alter the current PA rating. Our sensitivity analysis can be employed in cases in which an assessor must explain his/her ratings to assessment team members, as well as the organizational unit assessed. Six examples are provided to illustrate the applications of our sensitivity analyses. Copyright (C) 2011 John Wiley & Sons, Ltd.