In what sense is PD process modelling useful? and how can the utility of modelling be improved? In this paper, we approach these questions through an analysis of PD process modelling ‘utility’ – which in broad terms we consider to be the degree to which a model-based approach or modelling intervention benefits practice. We view the utility of modelling as a composite characteristic which depends both on the properties of models and on the way they are applied. The paper draws upon established principles of cybernetic systems in an attempt to explain the role played by process modelling in operating and improving PD processes. We use this framework to identify eight key factors which influence the utility of modelling in the context of use. Further, we indicate how these factors can be interpreted to identify opportunities to improve modelling utility.