Improving Off-Site Roof Construction through Lean Principles and Automation

Off-site Construction (OSC) meets rapid construction demands by shifting component fabrication to controlled factory environments, enhanced planning, and fast execution. This study investigates a real-world off-site roof construction scenario to address inefficiencies and delays. Using the PDCA (Plan-Do-Check-Act) cycle and Value Stream Mapping (VSM), manual panel framing and material loading are identified as key bottleneck processes due to inconsistent pacing and sequential handling. Lean Automation techniques are implemented to address these issues, along with a Thermwood Model 43 CNC Router for framing and a FANUC M-2000iA/2300 robotic system for loading roof panels. The proposed improvements are validated through simulations and demonstrate an overall system efficiency improvement from 0.68% to 1.52%. This research highlights how Lean principles, robotics, and digital tools can revolutionize OSC industrial practices, scalable to other OSC modules.