Digital transformation is fostering the evolution of the manufacturing industry, entering a new era of smart manufacturing. Manufacturers face challenges in integrating systems across manufacturing hierarchy, domain boundaries, and lifecycle phases. To benefit from the full potential of smart manufacturing, it is vital to take a realistic and stepped approach for manufacturing improvements. Improving the ROI and making smart manufacturing happen with an applicable implementation roadmap. The article illustrates the interconnecting process in smart manufacturing and introduces the Smart Manufacturing Kaizen Level (SMKL) to build up the capability at various stages of the implementation of DX. The article also provides actual lessons learned case studies, such as empowering workers' productivity and integrating OT and IT, to show the effectiveness of utilizing maturity performance management and capturing the values in smart manufacturing.