DisPMO and DePMO as six sigma‐based forward‐looking quality performance measures

Purpose – The purpose of this paper is to further develop a method to convert (dis)satisfaction on critical attributes (critical to qualities, CTQs) in the customer satisfaction survey into performance measures that are equivalent to defect per million opportunities (DPMO). Design/methodology/approach – Stepwise multiple regression analysis is applied to identify the CTQs, where the overall satisfaction is the dependent variable and the attribute‐related (dis)satisfactions (i.e. performance score minus importance score) are the independent variables. To simulate the attribute‐related (dis)satisfaction for the identified CTQs, random numbers that follow normal standard distribution are generated and returned into random numbers that have similar characteristics (properties) with the primary data. The proportion of returned random numbers below the lower six sigma limit (SL) and above the upper six SL is adjusted into dissatisfaction per million opportunities (DisPMO) and delight per million opportunities (DePMO), respectively. Findings – Applying the logic of DPMO outside the boundary of an organisation (i.e. in the market) leads to two distinct measures, DisPMO and DePMO. These two measures can be transformed into two types/variants of sigma levels, i.e. left‐side (approximated from DisPMO) and right‐side (from DePMO), which may describe organisational effectiveness in the market from two different but complementary approaches. Originality/value – DisPMO and DePMO provide a basis for assessing the effectiveness of an organisation (manufacturing/non‐manufacturing) according to six sigma methodology, where the “importance” and “performance” dimensions are considered simultaneously. Hence, the applications of DPMO (as six sigma's main performance measure) within and outside the boundary of an organisation are consistent and comparable.