In this paper we consider the way in which two representational forms, scenarios and design breakdowns, which have emerged in the traditions of human-centred design are relevant within the recent commercial emphasis on rapid application development (RAD). RAD is a contingent approach to interactive software development that is characterised by large amounts of user involvement, incremental prototyping and product-based project management. Scenarios have become popular as an intermediate representation within the human–computer interaction and computer supported co-operative work communities. Design breakdowns have been suggested as a useful organising device and design technique within the co-operative prototyping literature. Both these representational forms are not currently utilised within the commercial RAD tradition. In order to detail the relevance of these concepts to commercial development, we describe the ‘natural history’ of one particular RAD project and show how scenarios, breakdowns and the resolution of such breakdowns contributed to the successful implementation of an information system within a small commercial organisation. We conclude with a discussion of lessons from our work and some intended future work in this area.