In the Concept stage the client’s requirements are defined based on the Product Definition Statement. Specifications link these requirements and wishes to quantifiable product attributes.

Now different concepts, systems and forms may be developed. These are classified, evaluated and selected based on the specifications, breadboards, mock-ups, computer models and renderings. The goal of this stage is to supply a system, a concept and a design that ideally meet the client’s requirements and wishes.

In the Contract Book this concept is defined based on a requirement plan, a development, available and required budgets, detailed information about the selected concept and details about the non-selected concepts.