Microsoft® Office Project 2007 All-in-One Desk Reference For Dummies®

Chapter 3. Adding Dependencies

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✓	Exploring how dependency links affect timing
✓	Discovering the different kinds of dependency relationships
✓	Allowing for lag and lead time
✓	Establishing dependency links
✓	Reflecting the timing of external tasks in your project
✓	Viewing dependencies in Gantt Chart and Network Diagram views

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If you create 100 tasks and don’t change their default settings, they all start as soon as possible after the project start date. In the absence of timing relationships, called dependencies, all those tasks not only start on the project start date, but they occur simultaneously. That means that a project consisting of 100 tasks takes exactly as long to complete as the longest task.

Of course, that’s not a very realistic scenario for a project. Typically, tasks don’t happen at the same time. It might be impossible for certain activities to happen before others are complete, or you might not have the resources to perform two tasks at once. For that reason, you have to incorporate timing relationships that spread those tasks out through the life of your project.

Why Dependencies Are Needed

The reality is that tasks in a project can’t all start at the same time. To reflect that reality in a Project plan, you have to build in a timing logic. You build that logic into your plan by setting dependency links between tasks. Dependencies are timing relationships between tasks (for example, when one task can’t start before you complete ...