In nowadays, product quality is a basic factor for the factories for to protect and improve their competitive power both external and internal markets. Changing and developing market conditions force the factories to product-oriented managerial approaches. In this context, using of administrative tools aiming to increase the product quality is a basic necessity. Six sigma as a business management strategy is one of the tools to achieve the quality levels desired. Six sigma is consumer-oriented and aims the business success. This study was carried out in manufacturing lines of apparel factory. Aim of the study is to find out the resulting defects in sewing operations. DMAIC method which is the preferred in six sigma applications was used to find out defects in sewing operations. Collar, button-hole and button defects were frequently determined in the result of analysis of data obtain from sewing lines. Studies aiming to eliminate these defects were done in sewing operations. Important reductions were achieved in re-cutting, repair and pattern changing times. These reductions are respectively 78.1% (re-cutting), 77.4% (repair) ve 53% (pattern changing times).
