Kano Model - is a product development theory which categorizes customer requirements with respect to product features into below five segments.
1. Basic (must be quality) - as the name suggests, these are the basic expectations of a customer. If present, the customers are neutral, but if absent, it would lead to customer dissatisfaction.
2. Performance (one dimensional quality) - features that result in satisfaction if present and dissatisfaction if absent. These are the stated needs of the customer.
3. Excitement (attractive quality) - features that result in satisfaction if present and neutral if absent. These are the delighters for the customers. These needs are usually unspoken and are the differentiators for competing products.
4. Indifferent - features that the customer is indifferent to as their presence or absence neither causes satisfaction nor dissatisfaction to the customer.
5. Reverse - features that result in dissatisfaction if present and satisfaction if absent. These are the features that should not be present in the product.
Kano model is used to assess the product features on a periodic basis as the customer demands keep on changing. E.g. something that is an 'Exciting' feature today, will eventually become a 'Basic' feature tomorrow.
An application oriented question on the topic along with responses can be seen below. The best answer was provided by Arunesh Ramalingam on 17th October 2017.