Adding Link Lags

The value of the lag equals the number of days from the predecessor’s finish node and adopts the calendar of the predecessor activity. If a link had a lag of 7 days, and its successor were pulled back as far as it could go, the link would cease collapsing once the gap equaled 7. If a negative value is entered, this allows the start of the successor to push before the finish of the predecessor activity even when logic is on.

A lag displays as a red dot on top of the link, but it is not visible if the lag is too close to an activity node. You can also tell when a link has a lag in place by a red dot placed next to its gap value. This gives a cue that a lag is affecting the link gap value. Both the gap, and the dot next to the gap, however, will automatically be hidden if the gap reaches zero.

NOTE: Negative lags can only be applied to finish-to-start relationships. Upon opening a legacy schedule with negative lags on relationships other than finish-to-start, they will be removed automatically, a message will display, and the links with lags removed will become highlighted on the canvas.

Steps

1. With the Select Tool  chosen in the toolbar, double-click on a desired link, or right-click and choose Properties.
2. Under Properties, enter a number other than 0 next to Lag.
3. To display a red dot next to the gap value, check the box next to Lag Notation.
4. Click OK to close the window and apply the lag.

Notes

Lag Gap Calculation

Once a lag is defined, it affects the gap calculation. The gap of a link with a lag is calculated as the gap of the predecessor to the successor minus the lag value. In the following example, the original gap between the predecessor and successor is 5 calendar days.

Below, a lag of 3 calendar days is placed.

As you can see, the new gap of 2 days is equal to the original gap of 5 days minus the lag of 3 days.