Linking Energy Management and Optical Calibration Quality for Sustainable Automotive Electronics Manufacturing: An IMES Case Study of Rain and Light Sensors

Sustainable manufacturing requires managing energy efficiency and product quality jointly, yet automotive electronics plants typically handle them separately, despite sharing the same monitoring infrastructure. This case study examines a Volkswagen MQB-platform line producing headlight switching modules and windshield rain/light sensors (RLS), assessing the energy-saving potential of an Industrial Energy Management System (IMES) and RLS optical calibration as a source of avoidable retests and rejections. The energy assessment combined process analysis, published evidence and ISO 50001 requirements, without metering; the metrological assessment used calibration-bench data, automated test logs and end-of-line (EOL) records. Raising the correction factor from 0.02 to 0.03 increased the signal in all ten paired repetitions (+0.84% and +1.03%; paired t-test, p < 0.001) and reduced out-of-range Channel A readings from seven to one; linearity was not assessed. Test records without alerts accounted for 87.4–98.2%. All eight EOL units passed, yet positional deviations reached ±38.5 against a ±1.0 tolerance, warranting specification review. IMES adoption is projected, from the literature, to reduce energy consumption by 15–25% per unit. An energy-per-conforming-unit indicator links both: fewer false alerts, retests and rejections lower the energy, material and emission footprint of each sensor, supporting resource-efficient, low-carbon production (SDGs 9, 12 and 13).