Duration Type controls the way Primavera P6 manages the variables of activity duration, effort, and/or budget when adding multiple resources to an activity. It also affects these same variables when progressing the schedule with updates.
When a
schedule is in the planning phase it is typically a good idea to set the
duration type to fixed duration and units/time for most situation This is done
so that Primavera P6 honors your activity duration estimates and increases the
unknown work (units) and, therefore, the budget, based on additional required
resource effort (units/time).
Read the post on Ten Six
