Tracking real, on-site construction progress against the planned schedule (often the 4D model) using reality-capture data like drone photos or point clouds. A drone or 360-camera pass captures the site on a regular cadence, and that reality-capture data is compared against the 4D schedule model to flag what's ahead, on track, or falling behind - turning "how's it going out there" into an objective, model-based answer instead of a subjective site-visit impression.