Design Management Group

Kano model

Offers some insight into the product attributes which are perceived to be important to customers. An excellent tool to support product specification and a useful discussion tool to generate team understanding. Focuses the attention on differentiating features. Can be powerful when the full methodology is followed, but useful none the less as a visualisation tool.

Description

Developed in the 80's by Professor Noriaki Kano, the model is based on the concepts of customer quality and provides a simple ranking scheme which distinguishes between essential and differentiating attributes. The model is a powerful way of visualising product characteristics and stimulating debate within the design team. Kano also produced a rigorous methodology for mapping consumer responses onto the model. Product characteristics can be classified as:

Threshold / Basic attributes

Attributes which must be present in order for the product to be successful, can be viewed as a 'price of entry'. However, the customer will remain neutral towards the product even with improved execution of these aspects.

One dimensional attributes (Performance / Linear)

These characteristics are directly correlated to customer satisfaction. Increased functionality or quality of execution will result in increased customer satisfaction. Conversely, decreased functionality results in greater dissatisfaction. Product price is often related to these attributes.

Attractive attributes (Exciters / Delighters)

Customers get great satisfaction from a feature - and are willing to pay a price premium. However, satisfaction will not decrease (below neutral) if the product lacks the feature. These features are often unexpected by customers and they can be difficult to establish as needs up front. Sometimes called unknown or latent needs.

Product differentiation can either be gained by a high level of execution of the linear attributes or the inclusion of one or more 'delighter' features. But, it should be remembered that customer expectations change over time, and a cup holder in a car may be today's delighter, but tomorrow it will be expected. Some users of Kano also suggest that an additional set of attributes can be classified as 'enragers' - features which enrage either through their absence or inclusion.

Figure 1: the Kano model

Method

Kano developed a structured user questioning methodology to help characterise different features and remove ambiguity by ensuring that categorisation is based on user research. The methodology is relatively straightforward, as outlined below:

1. Determine main features, which need to be classified

Firstly, the features of interest need to be determined

2. Devise questionnaire

The questionnaire aims to understand how potential customers would feel if a feature was either present or not present. This is achieved by asking two questions for each feature - a functional question (ie - the feature is present) and a dys-functional question (ie the feature is not present), as shown in the diagram opposite.

3. Sum responses

As with any interview method, sufficient responses must be sought. An average response should be calculated.

4. Identify classification

Based upon the responses, the type of feature can be determined from a simple look-up table, as shown below. Note, there are some additional attribute classifications:

• Indifferent responses: these are attributes to which the customer pays no attention "If they are present, it is nice. If they are not present, it does not matter"
• Questionable responses and reversals: responses which contradict each other.

5. Plot features onto the Kano graph

Ideally, the features should be mapped onto the graph to provide a visual guide to the relative importance from a user perspective of different aspects of functionality.

Figure 2: The Kano charts: SMS texting is a Must for a mobile phone

Notes

• Can be difficult to grasp conceptually, but provides a useful additional dimension to specifying features - in addition to 'want', 'must have'
• Needs team involvement, as it links (like QFD) product features with user perceptions
• A good way of organising customer input
• Can be used without customer input as a visualisation tool

Further reading

• Kano, N., Seraku, N., Takahashi, F. and Tsuji, S. (1996) Attractive quality and must-be quality. In The best on quality, edited by John D. Hromi. Volume 7 of the BookSeries of the International Academy for Quality. Milwaukee:ASQC Quality Press.
• Center of Quality Management Journal (1993) Special issue on Kano's methods for understanding customer-defined quality , Vol 2, No 4, Fall 1993 (PDF - 350k)