The Performance-Importance Response Function: Observations and Implications

Services and products possess various attributes, some being more important than others. Importance-Performance Analysis (IPA) is a technique for prioritising attributes based on measurements of performance and importance. A weakness of IPA is that it conceptualises attribute importance as a scalar which is independent of attribute performance. In this article we theorise that importance is not adequately represented as a point estimate, but is a function of performance. When attribute performance changes, importance does also, which can change the relative priority of subsequent improvement efforts. Empirical results are presented which support our theory, The nature of the performance-importance response function is discussed, along with implications. Ideas for future research are also discussed, including application of the findings to quality modelling (SERVQUAL) and other decision support methodologies (Quality Function Deployment and the Analytic Hierarchy Process).