Classifying customer expectations, Noriaki Kano created the well-known Kano model more than 40 years ago. I felt this model deserves a more in-depth presentation on stars to road for a couple of reasons: First, it helps to prioritize features over the lifetime of a product. Second, it points to typical issues you encounter during product development and provides hints how to improve. Third, it is not too difficult to assess the categories and they are easy to understand. Fourth and most important: you need good understanding of customers and markets to work with the model, a real indirect benefit! All in all, the Kano model is an important foundation in product development one should know.