Overall Equipment Effectiveness (OEE) is quantifying process or entire production line by considering three main losses named time losses, performance losses and quality defect. It provides the measure of equipment so that corresponding optimization could be done. However, OEE had tolerated with many lean wastes which could be ‘invisible’ under its tradition definition. This includes unnecessary production which was classified as operating time and the underestimated effect of change over time. These could be minimized via work measurement, method study and study of the work, which are under the study of Maynard’s Operation Sequence Technique (MOST). This paper intends to quantify the lean waste in OEE from the perspective of method and work of an operation. Operations are analyzed in every single step using MOST and redesigning the work in favor of minimal non-value added activity in the operation or production. The OEE data before and after the study of work is computed and compared to examine its effect. It is expected to provide a new insight in implementing OEE at different way and stay beware of the assumptions in OEE to avoid any hidden waste.