Lag

Lag models real waiting time between two tasks — the classic example is waiting for paint to dry before the next step can begin. It is entered as a positive amount of time on the relationship itself, not as a task, so no resources are charged and no progress is reported while the Lag runs. Because a Lag is invisible in that way, it's worth considering a Schedule Visibility Task instead whenever the wait needs to be statused, is likely to differ from the planned delay, could land on the Critical Path or a Driving Path, or matters for traceability to other schedules. Unnecessary use of Lag can indicate a schedule that isn't modeling hand-offs at sufficient detail.

Why it matters

A Lag is quick to add, which is exactly why it gets overused. Time sitting in a Lag can't be statused, doesn't carry resources, and can quietly sit on the Critical Path where nobody is watching it. Every Lag should represent a real, explainable wait rather than a convenient way to push a date.

See also

FAQ