How To Display Lag between Tasks in Your Gantt Chart

By default, the lag set between tasks is displayed in the Predecessor column of the Gantt chart view. Neither Microsoft Project 2007 nor Project 2010 has a separate field to display the lead or lag of specific tasks.

You can display the lag as a separate field by following these steps:

1. In Project 2007 choose Tools, Customize Fields. In Project 2010 choose Project ribbon | Custom Fields in the Properties group.
2. In the Custom Fields dialog, select the Task radio button. Then choose the Type drop down and select Text.
3. Select Text1 and click the Rename button. Change the name to “Lag” and choose OK. This will display “Lag (Text1).”
4. Click the Formula button of Custom attributes, enter the following formula, and click OK:IIf(InStr([Predecessors],”+”)<>0, Mid([Predecessors],InStr([Predecessors],”+”),Len([Predecessors])), “”)You’ll get a warning message that existing data in the Lag field will be deleted because now all values will be calculated by the formula. Click OK.
5. Insert a column with the Field name as Lag (Text1) in Project 2007 by choosing Insert | Column. In the Field name dropdown, choose Lag (Text1). In Project 2010, just right-click on the column next to which you want the new column added and choose Insert Column. Scroll down to Lag (Text1) and select it.

You may be wondering about that formula I’ve asked you to enter. What does the code mean?

For the purposes of illustration, let’s say the lag between Prepare and Review tasks is 1FS+2days (translated to: “The task is planned to Start with a lag time of two days after the Finish of its predecessor task”).

The part of the code that specifies:

InStr([Predecessors],”+”)

returns the position of + in the [Predecessors] field. That’s four in the example shown in the screenshot.

This code:

Mid([Predecessors],InStr([Predecessors],”+”),Len([Predecessors]))

extracts the text from + to the end of the string, which is “+2days.”

If you want display the lag to the right or left of the task bar, follow these steps:

1. In Project 2007 choose Format | Bar Styles. In Project 2010, choose Format ribbon | Bar Styles in the Bar Styles group.
2. Select the rows in the top area that you want the lag displayed next to.
3. Select the Text tab in the bottom and choose the dropdown for Left or Right.
4. Select the field name Lag (Text1) and press OK.