Over the years, several studies have been conducted with industrial case studies on the application of the decision making grid (DMG) to improve maintenance strategies allocation. An important element of the DMG is its bound-ary classification as this has a direct impact on the determination of the particular strategy for the assets on the grid. Several studies have been conducted, and different methods of boundary classifications have been proposed and applied on the model. In all previous studies dealing with different methods of boundary classifications, the emphasis has always been on independent application of individual methods, thereby criticising one for the other. The current study however investigates the possibility of harmonising both approaches so as to enhance the robustness of the overall DMG as a decision making tool.