What Is Effort-Driven Scheduling in Microsoft Project?

What is Effort Driven Scheduling?

In short, effort driven in MS Project determines how task duration and work respond when resources are added or removed.

Effort Driven scheduling in Microsoft Project determines how tasks respond when you add or remove resources on a task that already has one or more resources assigned. By default, every task is Effort Driven unless you specify otherwise.

💡 Tip: Effort Driven ≠ Resource Leveling

Tip: Effort Driven scheduling is not the same as resource leveling. Effort Driven scheduling controls how work and duration are recalculated when you add or remove resources from a task. Resource leveling, on the other hand, resolves resource overallocations by delaying or splitting tasks. These two features are independent, and enabling Effort Driven scheduling does not automatically level your project.

Changing Effort Driven Status

If you need to change the Effort Driven status of a task, use one of the following methods.

Using the Task Entry View (aka “Split Screen” View)

• Apply the Gantt Chart view and then select the task in question.
• Right-click anywhere in the Gantt Chart screen and select the “Show Split” item on the shortcut menu to display the Task Entry view (“split screen” view).
• In the Task Form pane, select or deselect the “Effort Driven” checkbox, and then click the “OK” button.

Using Task Information Dialog

• Double-click the task to display the Task Information dialog.
• Go to the “Advanced” page, select or deselect the “Effort Driven” checkbox, and then click the “OK” button.

How Effort Driven Works

When you select the “Effort Driven” checkbox for any task, using one of the methods shown above, Microsoft Project designates that task as an Effort Driven task. When you deselect the “Effort Driven” checkbox for any task, Microsoft Project designates that task as a Non-Effort Driven task. Here’s how Microsoft Project handles both Effort Driven and Non-Effort Driven tasks, according to the Task Type of the Task. Each of the following examples assumes that you have previously assigned at least one resource to the task.

Fixed Units Tasks

• When you add an additional resource to a Fixed Units, Effort Driven task, Microsoft Project reduces the task’s Duration and splits the Work between each of the resources based on their Units values.
• When you add an additional resource to a Fixed Units, Non-Effort Driven task, Microsoft Project retains the task’s original Duration and adds Work to the newly assigned resource, based on its Units value.

Fixed Work Tasks

• When you add an additional resource to a Fixed Units, Effort Driven task, Microsoft Project reduces the task’s Duration and splits the Work between each of the resources based on their Units values.
• Fixed Work tasks are always Effort Driven because the work is automatically fixed or “locked” because of its Task Type. It is not possible to make a Fixed Work task a Non-Effort Driven task.

Fixed Duration Tasks

• When you add an additional resource to a Fixed Duration, Effort Driven task, Microsoft Project retains the task’s original Duration and splits the Work between each of the resources based on their Units values.
• When you add an additional resource to a Fixed Duration, Non-Effort Driven task, Microsoft Project retains the task’s original Duration and adds Work to the newly assigned resource, based on its Units value.

When Should You Use Effort Driven Scheduling?

✅ Good Candidates for Effort Driven Tasks

Use Effort Driven tasks when:

• The total work is fixed, but the duration can change
• Adding people should shorten the task
• Examples:
  • Development work
  • Documentation
  • Testing
  • Data analysis

In these cases, adding resources redistributes work and often reduces duration.

⚠️ When You Might Turn Effort Driven OFF

Consider Non-Effort Driven tasks when:

• The duration must remain fixed
• Adding resources increases total effort instead of reducing time
• Examples:
  • Training sessions
  • Meetings
  • Inspections
  • Review or approval tasks

In these cases, adding resources should not shorten the task — it should increase the total work.