During the past three decades, researchers have been advocating the application of define-measure-analyse-improve-control (DMAIC) phases of Six Sigma concept to achieve productivity and quality improvement in small and medium enterprises (SMEs). In this context, the research reported in this paper was carried out in a SME by applying DMAIC phases in the production of the castings of a component called balance weight. While executing the DMAIC phases, it was found that green sand moulding process had to be replaced with shell moulding process to avoid the increase in hardness and rejection of castings due to pin hole defect. On implementing this solution, the productivity increased by 50.42 units per hour and the quality level increased from 3.2 sigma to 4.4 sigma. Altogether, it was found that DMAIC can be used in SMEs to achieve productivity and quality improvement so as to acquire competitive strength. Copyright © 2020 Inderscience Enterprises Ltd.