As you might noticed that MS Project assumed (by defaulting) all tasks are efforts driven, what does this mean?
It means when MS Project do scheduling then it will maintain the Work value the same. Now you remember my equations in one post, if not I will put them again
- For Fixed Unit: U = W/D. In this case increasing the Work will result in increasing the Duration and visa verse
- For Fixed Duration: D = W/U. In this case increasing the Work will result in increasing the Unit and visa verse
- For Fixed Work: W = D * U. In this case increasing the Duration will result in decreasing the Unit and visa verse
Black color indication that MS Project will maintain the value of that field fixed when rescheduling
As per the options 1 and 2 you noticed that we fix either Unit or Duration.
By selecting the Effort Driven option the following should be considered
- If the assigned task type is Fixed Units, assigning additional resources shortens the duration of the task.
- If the assigned task type is Fixed Duration, assigning additional resources decreases the individual unit values for resources.
- If the assigned task type is Fixed Work, assigning additional resources shortens the duration of the task.
- Effort-driven scheduling only takes effect when resources are added to or removed from a task. Effort-driven calculation rules are not applied when you change work, duration, and unit values for resources already assigned to a task.
- The effort-driven calculations apply only after the first resources are initially assigned to the task. After the first resources are assigned, the work value doesn't change as new resources are assigned to or removed from the same task.
I hope this will help you