Deadline actually translates to total effort put in a task, which translates to total cost of the task, and Managers really need to know this to control the bud

Deadline actually translates to total effort put in a task, which translates to total cost of the task, and Managers really need to know this to control the budget. whether to develop a feature is based on cost vs benefit analysis, so if as a Manager I can't rely at all on the cost estimates then how can you be sure you are building the right thing in first place.