Estimate the Activity Durations

The total labor cost for emergency bridge rehabilitation on an interstate highway is $5,716,440.  The average crew-hour cost is $15,879 for this nonstop project.  The number of work days the roadway was shut down is most nearly:

Solution:  Assigning duration of actives is the estimated or actual time that it will be required to complete it. Accordingly:

  Total labor cost ÷ crew-hour cost = total crew-hours

  $5,716,440 ÷ $15,879 = 360 crew-hours

Nonstop project constitutes work at 24-hr 7-days/week

Total crew hours ÷ 24-hrs/day = project days

360 crew-hour ÷ 24-hrs/day = 15 days