Six sigma,   Rolled throughput yield, Organizational performance

Six Sigma is a well- established approach to improve the capability of business processes in order to gain satisfaction of customers. The performance assessment of a given process is essential to some phases of six sigma methodology. So far, different indicators are used to demonstrate the performance of a process, while many organizations tend to report their organizational performance level. Unfortunately there have been few methods on calculating overall performance. This paper introduces a quantitative model that is formulated by focusing on process features. In addition, a number of numerical examples illustrate the performance of our proposed method in comparison to other methods .