A key challenge in the development of systems is the engagement of domain experts in their articulation, agreement, and validation of requirements. This challenge is particularly pronounced at the early requirements phase when multiple stakeholders from different divisions and often different organisations need to reach agreement about the intended systems. Decisions taken at this stage have a profound effect on the technical and economic feasibility of the project. The S3 approach advocates the use of a modelling process expressed in terms of strategy-service-support dimensions, augmented by appropriate simulation techniques that enable experimentation with different scenarios. The S3 approach has been presented elsewhere. The aim of this paper is to provide insights from a large project in which the author played an active and interventionist part, on the utility of the S3 approach in facilitating stakeholder engagement in early requirements specification. The action research for this project involved the design of venue operations for the Athens 2004 Olympic Games. Many tens of stakeholders from a wide spectrum of professional expertise participated in the definition of business support systems for 21 competition venues over a period of 3 years. An interesting feature of this project was the use of three different approaches, starting with traditional peerto- peer knowledge transfer, followed by a typical business process modelling method and finally adopting the S3 approach and the way of working for the entire design of venue operations. The paper offers insights on all three approaches, insights that reflect on the problem of early requirements in general and on the validation of the effectiveness of the S3 approach in particular.