Most dev estimates are inevitably expressed in ideal hours. Even assuming no potholes, you need to multiply that by a load factor to get an approximation of rea

Most dev estimates are inevitably expressed in ideal hours. Even assuming no potholes, you need to multiply that by a load factor to get an approximation of real hours. Industry standard load factor is between 2-5x, typically around 3x when a team is up to speed. Therefore management need to multiply all estimates by 5 at the start of a project, ramping down to 3, and pray whilst adding some contractual contingency for the potholes. The corollary of this is that a management KPI can be to reduce load factor down to around 2 - which becomes a concrete measure of their effectiveness at removing impediments. (And yes this means that increasing productivity is a management task and not a developer issue.)