Whereas multimedia systems development (MSD) is inherently complex, and increasingly so, little is known about how multimedia designers manage or cope with this complexity. In particular, little is known about complexity beyond technical and process levels, and how such complexity impacts design activity. In this paper we construct a model of MSD based on the formulation of the broader concept of context complexity. This concept, which subsumes but also transcends technical and process complexity, is used to explain design strategies and their consequences. We identify four design contexts that explain, and are also explained by, complexity. These contexts map out the 'landscape for action' over which design activity takes place. They shape...