How do you effectively defend your infrastructure roadmap when vendor estimates promise a clean three-month cloud migration but the reality of refactoring legacy technical debt drags the project past a year? Furthermore, standard industry benchmarks reveal that simple lift-and-shift workloads might wrap up in mere weeks, whereas complex enterprise portfolios routinely require nine to eighteen months of execution. Why does underestimating the time needed for dependency mapping and stabilization consistently crash your post-migration budget?