Interactive prototyping—a challenge for computer based design

In the earliest stages of engineering design, where ideas and vague tasks predominate, the dynamics of interaction in creating and organising ideas are at least as important as the rather static and precise requirements for decision-making and for defining the product. A fundamentally different approach to the way that computers are programmed, in which computation is subordinated to interaction, provides new ways of modelling that are not constrained by preconceived modes of input and output. Models created by these means are extensible, reusable, multi-agent or concurrent. The user can construct and interact with a ‘virtual prototype’ as one might work up a physical prototype. The emphasis of the approach is manipulation and observation of application-specific knowledge, in an experimental environment that human users construct to mirror their own experience of the real world. The modelling method allows knowledge to be modified on line by the intervention of the modeller. The process offers immediate experience of the model behaviour and allows refinement of the design according to many viewpoints. It also assists in the decomposition of a system requirement into component requirements.