ABSTRACT
Even the best analytical methods are a shade removed from the real world of anticipated equipment function and predicted customer usage. At each step in the product or system design and development process, as real hardware and software become available, verification tests are performed to determine what works and what does not. What does not work to expectations can then be changed and improved. Prototypes can be patched or redesigned to meet specification criteria, customer demands, and company policy requirements. Design is fundamentally an iterative process with each step checked against real test results. Testing tends to remove uncertainty concerning product performance.
