prim35872:Why is the Resource Assignment’s duration not the same as the Activity’s duration?

1. Drive Activity Dates is switched off at the Resource Assignment level.


2. The Resource Calendars don’t allow the Resource Assignment to finish on the same exact hour as the activity.


3. The Duration Type of the activity is set to Fixed Units, or Fixed Units/Time and either the Budgeted/Remaining Units or the Budgeted/Remaining Units/Time were changed, thus recalculating duration of the resource.  If you have multiple resource assignments on that activity, then even if you have Drive Activity Dates checked, it will allow the resource to end sooner than the activity and will no longer match the activity’s dates.
   
   

When an Activity’s Start and Finish are the same as a Resource Assignment’s start and finish, changes made to the Duration of the Activity are pushed down to the Resource Assignment Level.  As long as the Start and Finish dates stay in sync, then changes made to the Activity’s Duration will be reflected in the Resource Assignment’s duration.

Fig 1:  Activity’s Start and Finish dates are the same as its Resource Assignment’s Start and Finish dates

Fig 2:  Changes made to the Activity’s Duration are “pushed down” to the Resource Assignment’s duration

If the Drive Activity Dates option is switched on at the Resource Assignment level, then changes to the duration at the Resource Assignment level will also be pushed up to the Activity level.

Fig 3:  Because Drive Activity Dates is switched on the Resource Assignment’s duration is “pushed up” to the Activity.

If the Activity’s Start and Finish dates are not the same as the Resource Assignment’s Start and Finish dates, changes made to the Activity’s duration will not be pushed down to the Resource Assignment’s duration and changes made to the Resource Assignment’s duration will not be pushed up to the Activity’s Duration:

If there is more than one Resource Assignment on an activity, then duration changes at the Activity Level will only be pushed down to those Resource Assignments whose Start and Finish dates match the Activity’s Start and Finish dates (and units will be allocated accordingly).

Fig 4: One of the Resource Assignment’s Finish dates differs from the Activity’s Finish date

Fig 5:  When the Activity’s Duration is changed, the change is only pushed down to the Resource Assignment whose Start and Finish dates match those of the Activity

Fig 6:  Changes to the duration of the Resource Assignment whose dates do not match the activity are not pushed up to the Activity’s duration, even though Drive Activity Dates is switched on for that Resource Assignment