Project 2007: Using Lag & Lead Time (Part 2 of 2)

This is Part Two in a two-part series on using Lag & Lead time in Microsoft Project 2007. Click here to read this article from the beginning.

Lead time is a head start you give a successor task. You will use lead time whenever you want a successor task to begin partway through the work of the predecessor task.As you can see in the above figure, a lead time of -50% has been added to Task 12's Finish-to-Start relationship with Task 11. In this case the time was entered as a percentage. You can also enter lead time as a negative number. This negative number (or percentage) tells Office Project 2007 that Task 13 can begin at a time equal to 50 percent of the duration of Task 12 (or after one day). Lead time creates overlapping Gantt Chart bars, also shown in figure above.

Even though there are technically two functions—lag and lead time—both of these numbers are entered in the Lag box in Office Project 2007. You enter lag time as a positive number and lead time as a negative number. Think of lag time as a buffer or “wait time” and lead time as a “head start” for the project tasks.

To enter lead time, follow these steps:

1. Create a relationship between two tasks.
2. Open the Task Information dialog box for the successor task.
3. View the Predecessors tab.
4. Enter a negative number or a negative percentage in the Lag column next to the task's predecessor.
5. Click OK.

If you decide later that the lead time is incorrect, you can change the lead time in a number of ways. You can open the Task Information dialog box again and use the Predecessors tab, or you can edit the lead time in the Task Dependency dialog box or in the Entry table. Remember, you add lead time in the Lag column or text box.

To change the lead time using the Task Dependency dialog box, double-click the link in the Gantt chart to open this dialog box and change the value in the Lag field as appropriate. To change the lead time in the Entry table, select the Predecessors column for the task and change the number after the - sign to the number you would like the lead time to be.

With permission from Microsoft Press, this article content was excerpted from the book, Managing Projects with Microsoft Office Project 2007 (Self-Paced Training Kit for Exam 70-632).