A lag in project scheduling is a delay between the start or finish of one task and the start or finish of another task. A lead is an overlap between the start or finish of one task and the start or finish of another task.
For example, if Task A has a 3-day lag before Task B may start, it signifies that there is a 3-day lag between the finish of Task A and the commencement of Task B. If, on the other hand, Task A has a 3-day lead before Task B, it suggests that Task B can start 3 days before Task A.
Lags and leads can be used to account for task dependencies and to fine-tune the schedule to better reflect the project’s actual duration.
