What Development Evidence Can and Cannot Show

A successful demonstration does not establish dependable service. A failed test does not establish a limit of physics. I examine this distinction through documented AAG aircraft-recovery and EMALS launch-system milestones. Four worked analyses show why operation counts alone cannot establish peak loads, reliability confidence, failure mechanisms or performance after configuration changes. The most instructive example concerns test design: a contrast that separates two explanations can leave others indistinguishable when interactions are allowed. Exact calculations also show how assumed count variability changes the repetitions needed for a specified decision. These are case-based analytical results and synthetic computations, not carrier measurements. The practical contribution is a traceable assessment sequence for choosing the next useful record, measurement or test.