1. Alteration made to a finished good or end-product or assembled component’s bill of materials by (1) adding or deleting a part, be it an assembly, subassembly, component, or material, (2) substituting an item with another (equivalency of capability), or (3) changing the usage of an item (intended use). 2. Alteration made in a system. Change can be functional, maintenance, performance, or physical characteristics. System can be mechanical, electrical, chemical, or computerization. Known also as task change.