1.5 Sigma Kaymanin Ýstatistiksel Kaymasi Nedenleri Uzerine Bir Arastirma

Six Sigma whose aim is perfect the processes was first introduced to the world by Motorola in the 1980s. Since then, those who follow the philosophy of Six Sigma has questioned why a specific shift must be added to process mean before estimating the capability of process. According to the Six Sigma literature, the value that must be added to the process mean is between 1.4 and 1.6 sigma, and generally 1.5 sigma is used for most processes. This study aims to seek answers to the questions which are why this correction is needed and why not any value but 1.5 sigma must be added to the process mean.