MS Project: Task Type and Effort Driven Scheduling
When assigning multiple work resources to a task, Microsoft Project performs a calculation to effectively schedule tasks and assign resources. This reaction to multiple work resource assignment can catch users by surprise and create confusion.
Work, Duration and Units
The calculation Project performs when multiple resources are assigned to a task depends on the Effort Driven Scheduling and Task Type settings. By default, effort driven scheduling is turned on and the task type is fixed units.
The calculation Project performs is;
Work = Duration * Units
This means that for a task taking 2 days with 1 work resource doing an 8 hour day the calculation is;
16 hours = 2 days * 8 hours
If another resource is assigned at a later time, project will recalculate this. Effort driven scheduling means that the work does not change. And the fixed units task type means that units will not change either. Meaning that the only option left for the formula to continue to work is for duration to decrease.
16 hours = 1 day * 16 hours (2 x 8 hours)
To stop this from happening you can change the task type to fixed duration so that the units decrease instead of the duration (each individual works 50% or 4 hours). Or remove the effort driven scheduling so that the work increases (32 hours for the example above).
Change the Task Type and Effort Driven Scheduling Option
For a Single Task
To change the task type or disable effort driven scheduling for a single task in the project;
- From the Gantt Chart, double click on the task name of the task you want to change.
- Click the Advanced tab of the Task Information dialog box.
- Uncheck the Effort Driven Scheduling box to disable effort driven scheduling, or click the Task Type list arrow and select another type such as Fixed Duration.
More MS Project Tutorials
Set the Default for all Project Tasks
It may be a better idea to change the default settings for all the tasks in the project. This can be done before entering any tasks into the project. It will not affect any existing tasks, they will need to be changed using the previous method.
- Click the File tab on the Ribbon.
- Click the Scheduling category from the left.
- Uncheck the All tasks are effort driven box to disable effort driven scheduling, or click the Default task type list arrow and select another task type such as Fixed Duration.