In the end of the engineering we’ve a prototype with a complete package of technical drawings and 2D/3D CAD files. This prototype is tested as far as possible on the basis of the proposed requirements. If the prototype doesn’t meet the product requirements, it will be adjusted or a whole new product will be developed. In that case the design process will start from the beginning again. Only when a prototype meets the proposed requirements the molds are made for production. It happens regularly that multiple prototypes were made before the design meets the product requirements. With the molds a first 0-serie can produced that also will be tested again. This 0-serie is also called a test serie.