Review of the Six-Sigma Methodology and Its Case Studies

The six-sigma is one of the most effective and recently developed business strategies to reduce process variability, keep on continuous improvement for the process, and to decrease cost and waste. Thanks to its popularity and success as a quality approach, it is commonly used in different manufacturing and non-manufacturing sectors. This study involves how the six-sigma approach is implemented in various sectors such as health care, manufacturing and areas like CRM (Customer Relationship Management), and process management by reviewing its measurement techniques, statistical tools, and applications together with the concepts of reliability and probabilistic design. We also cover computational and statistical methods to analyze the data and to compare relevant results in order to indicate the advantage of this approach.