Multi-projector preventive maintenance helps reduce unexpected downtime by checking the optical, mechanical, thermal and image-calibration condition of the projection system before visible problems become more serious. A practical maintenance plan may include projector inspection, lens and ventilation checks, filter service where applicable, alignment verification, brightness and color evaluation, calibration review and maintenance records. This guide explains how to build a preventive maintenance workflow for immersive, museum, mapping, dome, simulation and other professional multi-projector installations.