The popular approach to energy efficiency is replacing inefficient equipment, a plug-and-play method. However, much energy usage in operations remains hidden. To tackle this, we must illuminate and control this "black box". By employing Industry 4.0 principles, we can achieve this. Our Master Class mirrors TUBraunschweig's 40-hour "Die Lernfabrik" course and is uniquely tailored for Singapore's industry, conducted at ModelFactory@SIMTech.