Task Dependencies - Overview

Some project tasks cannot start until or finish before a related project task reaches a specific status. Project managers can create links between related tasks to define the dependencies that exist in the project schedule.

Tasks that affect the dates of other tasks in the project are called predecessors. Tasks affected by other tasks are called successors. For example, in a project Create Marketing Brochure, the task Edit Brochure Text cannot begin until the task Write Brochure Text is complete. In this example, Write Brochure Text is a predecessor of Edit Brochure Text.

Task Dependency Types:

Dependency Type	Description	Example
Finish to Start (FS)	Task A must finish before Task B can start.
Start to Start (SS)	Task A must start before Task B can start.
Finish to Finish (FF)	Task A must finish before Task B can finish.

Creating dependencies

You can create dependencies between tasks when you add a task, or by editing a task after it has been created. In the Gantt chart, task dependencies are created by dragging predecessor tasks onto dependent tasks.

For information about creating dependencies when adding a task, see Adding a Task.
For details about defining dependencies in the Gantt chart, see Setting Up Task Dependencies.

When setting up links between tasks, you can specify whether any lag or lead time is built into the dependency. For more information, see About Lag or Lead Time.