Currently approved performance-oriented specifications governing the development of Configuration Items (CI) that are a part of a higher-level CI, in which each specification defines the functional characteristics that are allocated from those of the higher-level CI, establishes the tests required to demonstrate achievement of its allocated functional characteristics, delineates necessary interface requirements with other CI, and establishes design constraints, if any, such as component/part standardization, use of inventory items, or logistics support (LS) requirements.