The Six Sigma Handbook, Revised and Expanded, 2nd Edition

3.4. KANO MODEL OF CUSTOMER EXPECTATIONS

3.4.1. Customer expectations, priorities, needs, and "voice"

Although customers seldom spark true innovation (for example, they are usually unaware of state-of-the art developments), their input is extremely valuable. Obtaining valid customer input is a science itself. Market research firms use scientific methods such as critical incident analysis, focus groups, content analysis and surveys to identify the "voice of the customer." Noritaki Kano developed the following model of the relationship between customer satisfaction and quality (Figure 3.6).

The Kano model shows that there is a basic level of quality that customers assume the product will have. For example, all automobiles have windows and tires. ...