There are many philosophies around how to evaluate a good product design.
I like to quote 2 sources of inspiration:
- The UX Pyramid:
- 8 Steps of an Intuitive Design from Everett McKay book that in my mind fits in the Conveniency/Pleasurable steps above.
The way I think about user experience and design is in 3 folds (in priority order):
- It has to be functional by solving the customer problem in a reliable way
- The experience is intuitive by being able to complete the task without reasoning, experimenting, documentation, training or memorization, and
- It is a delight to use it.