Prototyping. We use most of the processes currently available (SLA, SLS, DMLS, FDM, Vacuum Casting, CNC machining, conventional model making etc.) as appropriate for product development. There needs to be enough prototyping to adequately cover and prove out development. Prototypes are sometimes required at several stages during a project. This may vary from a single part for design validation or a small batch for product testing. Prototyping cost must be established at the project start as a balance has to be struck between prototyping and the risk of addressing problems later in the project when parts may have been tooled and are in production. It is well known that the cost of correcting a problem escalates as a project evolves. After tooling, it is many times that of correction at the prototype stage which in turn is many times that of a design stage correction. Suppliers such as toolmakers are involved here as the design benefits greatly from reviewing a physical model.