The term Voice of the Customer (VOC) is used to describe customers’ needs and their perceptions of a product or service and includes all forms of interaction between customers and an organization.  The VOC data helps an organization to align design and improvement efforts with business strategy and decide what products, processes and services to offer or enhance.  Additionally it helps to identify critical features/performance requirements for products, processes, and services as well identifying the key drivers of customer satisfaction.

Data collection and analysis is also a major aspect in collecting VOC data and more information on this can be found in the data collection notes.

Affinity diagrams and the Kano model are useful tools for collecting and analyzing VOC data. 

Noriaki Kano is a renowned Japanese expert in total quality management. His practical experience with understanding customer requirements led him to define three categories of customer needs:

• Must Be:  These needs are expected by the customer. If they are unfulfilled, the customer will be dissatisfied, and moreover even if they are completely fulfilled the customer would not be particularly satisfied (e.g., airline safety).

• Satisfiers:  These needs have a linear effect on customer satisfaction—the more these needs are met, the more satisfied these customers are (e.g., cheap airline tickets).

• Delighters: These needs do not cause dissatisfaction when not present but satisfy the customer when they are (e.g., airline that serves hot chocolate chip cookies en route).

Use of the Kano model is to ensure that no critical needs have been omitted.  For example:

• List all the needs and categorize them as must-be’s, satisfiers, or delighters

• Make sure that no must-be need has been inadvertently missed

• If delighters are few, try to identify others, or enhance the VOC study—competitive advantage is gained through delighters

Quality Function Deployment (QFD) is the formal tool used to prioritize requirements and uses quantitative importance ratings of needs. The richness of the QFD approach is lost if quantitative prioritization data is not available. Whenever possible, quantitative data should be collected through surveys.  See lecture notes on QFD.

Once VOC data is collected and prioritized then it needs to be translated into requirements.