In operational testing, an implicit assumption that is often made is that the system design is basically mature and that, barring unusual circumstances, the system will soon be purchased and fielded. Therefore, the system is typically not stressed at excessive levels. Instead, the testing roughly is guided by the typical scenarios of use (e.g., as promulgated by the U.S. Army’s formal Operational Mode Summary/Mission Profile document). The objective of operational testing is usually stated as to confirm that the system satisfies its operational requirements. This means that significance tests at standard statistical levels would fail to reject the null hypothesis that the system’s performance satisfied its requirements. (The requirements are often stated in terms of averages over scenarios of use, in which the scenarios and their frequencies are governed by the Operational Mode Summary/Mission Profile document.)
Early operational assessments occupy a middle ground between developmental and operational testing. They may involve component testing with typical users or other means of gleaning operationally relevant insights.