p90 cost estimate definition
In the context of Figure 4, the P50 cost is represented as âcâ dollars. The P50 estimate is one with equal chance of project overruns or underruns up till when the project scope can be finalised. The P90 value is an estimate of the project cost based on a 90% probability that the cost will not be exceeded.his arises as the P90 cost estimation was adopted at the early stage during project scoping. Had the P50 cost estimate been adopted, there would have been a deviation of $7 million between the actual ($69 million) and budgeted P50 figure ($62 million). The project would have been under-budgeted.