Kang et al. Modern OO methodologies directly address these points and emphasize the incremental, iterative, evolutionary, concurrent and situational nature of software development. Seamlessness together with naturalness is a big advantage for consistency. A problem domain has many realizations, or differing OOAs. An OOA has many realizations, or differing OODs, but a similar notation is often used for the two.
Every project is handled similarly.
A measurable basis for all improvements to the process.