Final adjustments are carried out according to the test results in the previous phase. Phases 3 through 5 can be repeated as specifications may change during the ongoing development process, in order to optimize the end product further. It is imperative for the best end result that changes are handled in a unbureaucratically manner.
Functionality is completed and all specifications are approved by the customer. The parts list is revised and completed. Test documentation and production documentation are completed. Manufacturing tools and equipment are constructed.