Explanation/Reference:
Cost and work is here least flexible. If total work effort or fixed costs are most important, choose Fixed
Units.
Note: Working with Duration Types
Duration type options
Duration type determines whether the schedule, resource availability, or cost is most inflexible when
calculations are performed to reflect activity progress. Duration type affects update calculations only when
resources are assigned to an activity.
Choose a duration type based on which factor is the most important, or least flexible, in planning your
project.
If schedule is most important, choose Fixed Duration and Units/Time or Fixed Duration and Units.
If resource availability is most important, choose Fixed Units/Time.
If total work effort or fixed costs are most important, choose Fixed Units.