Definition
In project management, lag refers to the intentional delay between dependent tasks in a project schedule. It occurs when a successor task cannot start immediately after its predecessor is completed, creating a waiting period before progress can continue.
Why Lag Occurs
- Resource availability constraints – Waiting for materials, personnel, or approvals.
- Process requirements – Allowing time for curing, drying, or testing (e.g., concrete drying in construction).
- Dependencies – Tasks that inherently require a delay (e.g., waiting for customer feedback before moving to the next phase).
Example
In a construction project, if workers pour concrete for a foundation, they must wait for it to dry before installing flooring. This waiting time is considered lag and is built into the schedule.
