AACE Planning & Scheduling Professional (PSP) Certification Practice Exam 2026 - Free PSP Exam Practice Questions and Study Guide

A lag in scheduling specifically refers to a delay that is intentionally inserted between two logic-linked activities. This means that when one activity finishes, a certain amount of time must pass before the next activity can start, regardless of whether the preceding activity finishes early or on time. This concept is essential in project schedules as it helps account for scenarios where there are dependencies between tasks that require waiting time, such as curing time for concrete or other factors that necessitate a gap.

Understanding lags is crucial for creating realistic and executable schedules that accurately reflect the conditions and constraints of a project. By effectively managing lags, planners can ensure that resources are available as needed and minimize potential bottlenecks caused by overlapping or tightly scheduled tasks.