To assure the expected operational and developmental system quality is actually delivered, a test-driven approach to architecture elaboration is a powerful tool. Evaluations, simulations, and running code provide direct feedback as to whether a system's architecture and implementation support its quality requirements. Test-driven design is also a fantastic vehicle to check if the specified qualities are sufficient for providing the expected value. Unless you physically experience the system, all its requirements, especially quality aspects, are just assumptions. Thus, you might need to adjust the assumed quality requirements when you see the system in action. The quality/ value feedback loop closes.