Integration is a process by which components are aggregated to create larger components. Integration testing is testing done to show that even though the components were individually satisfactory, as demonstrated by successful passage of component tests, the combination of components are incorrect or inconsistent. An item is a non-specific term used to denote any product, including systems, subsystems, assemblies, subassemblies, units, sets, parts, accessories, computer programs, or computer software. An NDI is any item that is available in the commercial marketplace or elsewhere, including COTS, GOTS, or any previously developed item that is either in use or not yet in use. Operational testing is performed by the end user in an operational environment.
Performance is a quantitative measure characterizing a physical or functional attribute.
Performance requirements define the extent to which a mission or function must be executed, generally measured in terms of quantity, quality, coverage, timeliness, or readiness. A probe is an external means of accessing data within a system component. Qualification testing deals with tests of the hardware, e.g., maintainability demonstrations, reliability demonstrations, environmental tests, human factors, etc. Regression testing is selective testing to verify that modifications have not caused unintended adverse side effects or to verify that a modified system still meets requirements. A subsystem is a set of interrelated elements satisfying a logical group of functions within a particular system.