Reviewing Kano's model

I recently dug up an old, seminal paper on customer delight that I'd been meaning to read. I've been coming back to the topic a lot lately while building a side project of my own.

Noriaki Kano's 1984 model explains why fixing everything people complain about never adds up to something they love. It sorts what a product offers by how it affects satisfaction. He does it with a really clever trick: ask people how they'd feel if a feature were there, then how they'd feel if it weren't, and the pair of answers reveals its kind. For a team, that becomes a way to prioritize. Some things you meet and then leave alone, some are where you compete, and some are where you stand out.

I read it next to my own Product Delight framework expecting the two to diverge in places. Instead they reinforced each other from opposite perspectives: Kano from the customer's, mine from the team building the product.

Where it came from

The model came out of Japan trying to understand America trying to understand Japan, which I find genuinely funny. Engineers from Lockheed visited Japan in the early 1970s to study quality circles, and when the practice didn't take back home, Kano was sent to find out why. In Japan, engineers ran the circles. In the US, behavioral scientists and industrial psychologists did, and they focused on motivating workers more than on the mechanics. Kano didn't so much fix that as learn from it. Digging into the same motivation research, he found that what keeps workers from being unhappy isn't what makes them happy, and he asked whether customers judge products the same way.

Three requirements

Kano's requirements reflect how people feel about products or services, from what they quietly expect to what they never thought to ask for.

• Must-be: taken for granted. Meeting it earns nothing; missing it loses everything.
• One-dimensional: asked for by name. Satisfaction rises and falls in proportion to how well it's met.
• Attractive: unexpected. Missing it costs nothing; meeting it delights.

Example: a clean hotel room prevents disappointment; a cleaner one creates no delight. That's must-be. A bigger bed rewards every improvement: one-dimensional. A handwritten note on the pillow pleases, and nobody misses it when it isn't there: attractive.

must-bethe room is clean

Mostly clean. Still uneasy; nothing earned.

one-dimensionalthe size of the bed

A double. Fine.

attractivea note on the pillow

A printed card. A small smile.

Discovering requirements

You find a requirement's kind by asking two questions: how do you feel if the product has this, and how do you feel if it doesn't? An evaluation table turns the pair of answers into a category.

1 · Pick a requirement of a hotel room

The room is cleanThe wifi is fastYou can check in from your phoneA handwritten note on the pillow

2 · Answer the functional form

If the room is spotless when you walk in, how do you feel?

I like itIt must be that wayI am neutralI can live with itI dislike it

3 · Answer the dysfunctional form

If there is a hair in the bathtub, how do you feel?

I like itIt must be that wayI am neutralI can live with itI dislike it

4 · Read the tableAnswer both questionsThe pair of answers lands in one cell of the table on the right. This requirement is the floor of any stay.

	like	must	neutral	live with	dislike
like	Q	A	A	A	O
must	R	I	I	I	M
neutral	R	I	I	I	M
live with	R	I	I	I	M
dislike	R	R	R	R	Q

rows: functional · columns: dysfunctional

Comparing Kano and Product Delight

Product Delight sorts the moments in a flow into three tiers:

• Baseline: the experience works as promised, fast and reliable with nothing in the way. Gut check: does it just work? It earns trust.
• Enhanced: the details and foresight are palpable, and the craft goes a little further than anyone expected. Gut check: does it feel like someone cared? It earns appreciation.
• Signature: a moment distinctive enough that people want to share it. Gut check: would someone say "take a look at this"? It earns loyalty.

Baseline and must-be are the same idea; so are signature and attractive. At first the middle looked like the place they disagree, but then I looked a little closer and I think it's the same place, seen from two sides.

Kano defines each category by how the customer responds, and one-dimensional is what people ask for by name: a bigger bed, faster wifi. Enhanced starts from the other side of the screen. It's an appeal to a team to look at each design lever (motion, visual language, physics, content, personalization) and decide where to invest in craft, in an industry that often trades quality for speed.

For the team, those levers are one-dimensional: more care, better work. For the person, they land closer to attractive. Nobody asks for a phone charger waiting on the nightstand, and nobody misses it when it isn't there. What they notice is a gradual realization that someone cared. Kano's attractive is a surprise; enhanced accumulates. I don't think it would be better as a number. Working out what care looks like is exactly the kind of ambiguity a team should tackle together.

What surprised me most: requirements decay

Requirements don't stay put. Kano calls it the life cycle of attractive quality. In 1985 a TV remote was "wow, nice." By 2000 it was "obviously it has a remote." Today a TV without one would make people angry.

Airbnb has made the same slide. Punching a code into a keypad lock and letting yourself in once felt like magic, with no front desk and no handing over keys. Now it's what guests expect, and a host who asks you to meet them for the keys feels like friction.

So a signature moment has a shelf life, and the only way to know when it's expiring is to stay in dialogue with the people you design for.

What I'm still working out

• I'm still unsure about identifying, or creating a formula around, signature moments. Some of the best ideas come from people talking about ridiculous things they could do and getting excited. Not everything needs a formula.
• I'll probably add the two questions to my product delight skill: the functional form, how do you feel if the product has this, and the dysfunctional form, how do you feel if it doesn't. The pair of answers sorts the requirement.

Sources

• Kano, N., Seraku, N., Takahashi, F., Tsuji, S. (1984). "Attractive Quality and Must-be Quality." Hinshitsu 14(2), pp. 39–48.
• Matzler, K., Hinterhuber, H. H., Bailom, F., Sauerwein, E. (1996). "How to delight your customers." Journal of Product & Brand Management 5(2), pp. 6–18. The paper I read, in its Innsbruck preprint.
• Kano, N. (2001). "Life Cycle and Creation of Attractive Quality." Proceedings of the 4th QMOD Conference, Linköping. Source of the life-cycle idea.
• Interview with Professor Noriaki Kano, Chartered Quality Institute. Source of the remote example and the origin story.