Abstract Extensive technical literature exists aimed at establishing the requirements needed to qualify a Nuclear Power Plant model. Most of this literature is focused on qualifying a model for licensing uses. Less documentation is available nowadays on the requirements needed when an Integral Plant Model is used for supporting plant operation and control of an actual commercial facility, while fulfilling its goals of safety and competitiveness. For the last 15 years the Technical University of Catalonia (UPC) has been working in this field along with Asociacion Nuclear Asco–Vandellos (ANAV), which is a utility that presently runs three operating PWRs. The paper develops an advanced qualification process (AQP) of plant models for operation support, introduces the concept of plant configuration and explains how this activity complements other usual validation tasks.