Overhauls

oh-ver-hawlz (noun) Overhauls are comprehensive, systematic examinations and complete renovations of existing systems, processes, or structures to bring them up to current standards or requirements. They involve taking something apart entirely, identifying what's broken or outdated, and rebuilding it from the ground up rather than just making small adjustments.

Think: the difference between getting your car serviced versus completely rebuilding the engine — one's maintenance, the other's a total reconstruction job.