Effort-Driven Tasks in Project 2013
When you hear the word effort in Project 2013, think work. For a task that’s automatically scheduled, you can also set it up to be effort driven: If you adjust resource assignments, the duration might change, but the number of hours of effort (work) resources needed to complete the task stays the same. (Effort-driven scheduling isn’t available for manually scheduled tasks.)
When you add or delete a resource assignment on an effort-driven task in Project 2013, work is distributed equally among resources. In fact, all fixed-work tasks are effort driven. The more people you add, or the more hours they work, the shorter the duration, and vice versa.
Suppose that you need to set up a computer network in a new office in two days. You assign to this task one resource who works 8 hours per day, so the work will take 16 hours to complete (two 8-hour days).
If you then assign a second resource, this effort-driven task no longer takes two days, because the hours of effort required will be completed more quickly by the two people working simultaneously — in this case, in one 8-hour period.
Behind the scenes, effort-driven scheduling uses this formula to work this “magic”:
Duration = Work ÷ Units
After you make the first assignment, any time you add or remove more units (people), Project recalculates the duration accordingly.
Adding resources doesn’t cause a task to be completed sooner — in fact, the behavior changes from fixed work to fixed duration. Select the Effort Driven check box on the Advanced tab in the Task Information dialog box to enable or disable the Effort Driven setting; it isn’t selected by default.
When you clear this check box, the same task that you set to run two days takes two days, no matter how much effort your resources contribute.