The philosophy of end user design proposes an approach to information systems provision where those involved in the human activity context are central to establishing the relevant requirements for their information systems. In this paper we develop the case for centering definitions and process flows on end users in their active situations. We examine the potential for basing integrated IS development upon the constructive and evolutionary processes in the client context. Provision of enterprise-wise IS design environments in which this approach becomes realistic implies a systemic reappraisal of the role of software engineering methods and their place in IS design. With reference to case studies we consider some organisational characteristics in which evolution of specific information systems can be achieved through provision of such design environments. Representative situations at the level of full application design and customisation, workflow definition and enterprise-wide development are considered.