This stage consists of refining the preferred concept in order to establish and communicate the final solution, prior to more detailed work.

Typically, there is a greater emphasis on 3D CAD, including 3D solid modelling, part assemblies, fit checking, photo-realistic computer images, colourways exploration, patent issues, visual appearance models or test-rigs.

A finished model will define what the final product will be like, so that both marketing & technical teams can sign off the design intent.