Six Sigma provides an effective mechanism to focus on customer requirements, through improvement of process quality. In the Global Engineering Development Center of Tata Consultancy Services (TCS - GEDC) at Chennai, India, Six Sigma projects are being carried out with the objective of improving on time delivery, product quality and in-process quality. This paper describes the application of the Six Sigma methodology comprising the five phases - Define, Measure, Analyze, Improve and Control, by taking the example of a project, and demonstrates the benefits attained.