Testing and validation processes are a vital part of all steps of the system engineering V-model (a framework for testing and validation, illustrated in Exhibit 1). Typically they account for 20 to 30 percent of development costs. In the preconcept phase, great companies test customer perception of the planned product in order to optimally design the product to customer needs and to improve probability of market success. In the early development phases, virtual tools are used to ensure that the different components fit together, that the product can be built, and that all functional requirements are met. In later stages, all kinds of tests are required, for example, to ensure safety and environmental requirements are met, durability is proved, and so on. Finally, close to production, testing reveals whether the product can be built, quality is demonstrated, and final checks before the start of production are made.

Validation is the process of determining if the completed product fulfills the customer’s expectations and criteria. It is a dynamic validation and testing technique for the real product.