If politicians get to call the shots in any way, it's going to run way over budget. Pretty much every single time.
My son talks a lot about a study that showed optimists badly underestimated how long a project would take. So did pessimists, though their estimates were less egregiously wrong.
Basically, if people are involved, you can assume that budgets and time estimates are hand-wavy, ballpark guestimates at best.
Life will get in the way. Even people who truly understand that will fail to accurately predict just how much life will get in their way.
My son talks a lot about a study that showed optimists badly underestimated how long a project would take. So did pessimists, though their estimates were less egregiously wrong.
Basically, if people are involved, you can assume that budgets and time estimates are hand-wavy, ballpark guestimates at best.
Life will get in the way. Even people who truly understand that will fail to accurately predict just how much life will get in their way.