Lag
Scheduling Terms
Reviewed by forProject Technology - updated Sep 2026
Quick definition: A Lag is a delay built into a logical relationship, holding the successor task back for a set amount of time after the predecessor condition is met.
Lag is a delay applied to a logical relationship to impose a "gap" between two tasks. It's entered as a positive amount of time on the relationship itself, not as a task, so it carries no resources and can't be statused. When the wait needs tracking or could affect the Critical Path, a Schedule Visibility Task is usually a better choice. Overuse of Lag can mean the schedule isn't modeling hand-offs in enough detail.
What this means for you
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.
Also known as
N/A
Used in
Schedule network modeling; Critical Path Method calculations; schedule health assessment
FAQ
How is a Lag different from just adding a task?
A Lag is an attribute of the relationship between two tasks, so it has no duration of its own to status and no resources assigned. A Schedule Visibility Task models the same wait as a real task, which can be statused and tracked — generally preferable where the wait matters.
Can a Lag be entered as a percentage?
Some tools allow it, but it's best avoided: a percentage-based value moves with the predecessor's duration, so it can drift as the schedule changes.
Definition maintained by forProject Technology.
© 2026 forProject Technology, Inc.
© 2026 forProject Technology, Inc.
