Completeness
Completeness — more fully, functional completeness — is the degree to which a system’s set of functions covers all the specified tasks and user objectives it was designed to address. It is a quality attribute defined by ISO/IEC 25010, and one of the sub-characteristics of functional suitability, alongside correctness.
Where correctness asks whether a function produces the right results, completeness asks a different question — whether the full set of required functions exists at all. A system can implement every one of its functions correctly and still fail on completeness if some specified task or user objective has no function addressing it.