Answer:
estimation phase
Step-by-step explanation:
The Estimation process is more useful to allow trade offs in terms of labor and cost of equipment to reduce the building project period.
That's because it's good to manage the period of operations and during time estimation cycle and preparation of critical path and network, but if they try to do it at the time of construction, there are several factors that make it complicated and can affect prepared network failure.
Therefore it is the case of estimation phase