Abbas Saghaei - Science and Research branch, Islamic Azad University
Hoorieh Najafi - Science and Research branch, Islamic Azad University

Six Sigma is a well- established approach that seeks to identify and eliminate defects, mistakes or failures in business processes or systems by focusing on those process performance characteristics that are of critical importance to customers. The performance assessment of a given process is essential to some phases of six sigma methodology

Six sigma, Rolled throughput yield, Organizational performance