4: Duration Types

Duration Type is a feature which lets you specify the behaviour of the following:

  1. Activity Duration
  2. Assigned Resource Units (Budgeted Units)
  3. Assigned Resource Units/Time (Remaining Units/Time)

Primavera P6 lets you control these settings by way of 4 Duration Types, as follows:

  1. Fixed Duration and Units
  2. Fixed Duration and Units/Time
  3. Fixed Units
  4. Fixed Units/Time

Fixed Duration and Units: This is used with Task Dependent activities. As we know, in Task Dependent activities, duration is fixed. Additionally, the assigned resource units are also fixed. This Duration Type is used when the schedule (time) is more important than the availability of resources or total work effort.

Example, 100 units are assigned to an activity of 10 days duration. This means 10 units must be executed daily. Accordingly, P6 will show the Units/Time = 10/day. Suppose after 1 day, only 1 unit is performed. Now 99 units are remaining with 9 days available. After properly updating the activity with this information, P6 will recalculate the Remaining Units/Time as 11 (i.e. 99 Units/9 days) so that the final tally of units matches the 10 days and 100 Units originally assigned.

As can be observed, the Duration and Units are kept fixed and only the Units/Time are adjusted to satisfy the assigned setting.

Fixed Duration and Units/Time: This setting is also used in case of Task Dependent activities, with the only change being that the total units can be varied keeping the Duration and Units/Time constant. This setting is used when the total output required is unknown and how much can be produced in a day is the governing factor. With this setting in the above example, the Units/Time for the remaining days will not be changed resulting in lesser number of total units at the end of 10 days.

Fixed Units: This Duration Type is used with Resource Dependent activities in cases where the total work effort is most important (known, or fixed).

Fixed Units/Time: This type indicates that availability of resources is the governing aspect, therefore the Units/Time are fixed and the Duration and Units can be varied. This type is also used with Resource Dependent activities.