Requirements specification methods and techniques have hitherto mainly been concerned with promoting various representation formalisms for formally describing information systems. However the emphasis on system modelling is shifting to process modelling. Our concern is the modelling of the Requirements Engineering (RE) process. The particular RE process modelling approach presented in the paper emphasises the notion of RE decision within the context in which it is taken. The context of decision is defined as a means to proceed locally as well as globally in the RE process. The paper concentrates on the presentation of the contextual approach and its illustration through examples extracted from the case studies developed in the Esprit project F3* where this approach is defined and experienced in user companies projects.