DMAIC methodology is fundamentally viewed as a process that focuses on improvement and variation reduction through the use of DMAIC improvement projects. With globalization and the fourth industrial revolution, organizations are obliged to put in place mechanisms that champion process efficiency. This study used the DMAIC concept into productivity ‘gap’ reduction between planned shift work Time on the steel manufacturing production line and the actual shift work Time on the line in a manufacturing Industry. After the ‘gap’ activities are recorded, the ‘gap’ analysis is conducted using the causes and effect diagram and Pareto charts. And the outcome has revealed areas that have contributed to the Line Manager's (LM) daily routine inefficiency, among which include ‘meetings’, ‘scanning’, ‘follow-up’, ‘walking’, and others. The proposed improvement is listed for both the “out of Line Manager’ control” ‘gap’ activities and the” within Line Manager’ control” ‘gap’ activities. The study recommends the restructuring of work tasks and systems in order to optimize LM’s productivity and improve motivation.