The Kano model: Critical to quality characteristics and VoC

Dr. Noriaki Kano, a very astute student of Dr. Ishikawa, developed an interesting model to address the various ways in which Six Sigma practitioners could prioritize customer needs. This becomes particularly important when trying to rank the customer’s wants and desires in a logical fashion.

The practical side to the Kano model

The Kano model is a tool that can be used to prioritize the Critical to Quality characteristics, as defined by the Voice of the Customer, which I will explain in greater detail below. The three categories identified by the Kano model are:

• Must be: The quality characteristic must be present or the customer will go elsewhere.
• Performance: The better we are at meeting these needs, the happier the customer is.
• Delighter: Those qualities that the customer was not expecting but received as a bonus.

What is the first step for creating the Kano model?

Identifying the Voice of the Customer

The first step for creating the Kano model is to identify the quality characteristics that are typically fuzzy, vague and nebulous. These quality characteristics are referred to as the Voice of the Customer (VOC). Once the Voice of the Customer is understood, we can attempt to translate it into quantitative terms known as critical to quality (CTQ) characteristics.

This should not be a new concept for those familiar with the Six Sigma methodology. What happens from here, though, can sometimes go astray if we are not careful and try to put our own spin on the needs of the customer. This may be the result of trying to make things more easily obtainable for us—a formula for failure.

Use the Kano Model to prioritize the critical to quality characteristics

So, now that we have identified what is important to the customer in workable terms, we can go to the second step. Always keeping the customer in mind, we can apply the concepts outlined in the Kano model diagram. 

The Kano model is broken down into an (x, y) graph, where the x-axis of the Kano model represents how good we are at achieving the customer’s outcome(s), or CTQ’s. The y-axis of the Kano model records the customer’s level of satisfaction as a result of our level of achievement.

The red line on the Kano model represents the Must Bes. That is, whatever the quality characteristic is, it must be present; if the quality characteristic is not met, the customer will go elsewhere. The customer does not care if the product is wrapped in 24-carat gold, only that it is present and is functionally doing what it was designed to do. An example of this would be a client who checks into a hotel room expecting to find a bed, curtains and bathroom in the room. These items are not called out for by the customer, but would definitely cause them to go elsewhere if any of these "characteristics" were not present.

The blue line on the Kano model represents the Performance. This line reflects the Voice of the Customer. The better we are at meeting these needs, the happier the customer is. It is here where the trade-offs take place. Someone wanting good gas mileage would not likely expect to have a vehicle that has great accelerations from a standing position.

By far, the most interesting evaluation point of the Kano model is the Delighter (the green line). This represents those qualities that the customer was not expecting, but received as a bonus. A few years ago, it was customary that when a car was taken back to the dealer for a warranty oil change, the vehicle was returned to the owner with its body washed, mirrors polished, carpets vacuumed, etc. After a few trips to the dealer, this Delighter became a Must Be characteristic. Thus, a characteristic that once was exciting was now a basic need, and a part of the customer’s expectations. Another example of this is the amenities platter that some hotels provide their platinum customers upon checking in. I am one of those clients entitled to such a treat. This practice was certainly a delight. It has, however, become an expected part of my check-in, such that if there is no platter waiting in my room, I am on the phone with the front desk.

Once the critical to quality characteristics have been prioritized, the last step of the Kano model involves an analysis of evaluating or assessing just how well we can satisfy each of Dr. Noriaki Kano’s classifications.

Kano model case study

Being a trainer and consultant, I spend a lot of time on the road. In doing so, I have a tendency to check into hotels on a regular basis, as mentioned earlier. I once queried the manager of a hotel I spend a lot of time at on how he established practices to entice the business client. He related the following scenario to me.

The first thing he did was identify a list of qualities the client would be interested in. He came upon his list by listening to complaints, handing out surveys, holding focus groups and conducting interviews. The information below is a partial list from the Voice of the Customer. Knowing that I was involved in something that dealt with customer satisfaction, he asked me to assist him in ranking the characteristics. I explained the concepts behind the Kano model, and together we developed the list in the column labeled Business Client, as shown in Table 1. This was all fine and dandy, as far as the business customer was concerned.

Table 1

For my own interest, I asked him to look at these same characteristics from the point of view of a vacationing family. As a final task, I asked him to assess how strong or weak he felt the hotel was when trying to meet those quality characteristics identified in table 1.

The results are shown in Table 2.

Table 2

The conclusions from this effort can be as summarized by looking at the rows that have a characteristic in the Must Be category. With respect to the business client, this yielded express checkout, a comfortable bed, continental breakfast, internet hook-up and newspaper. The vacationer, on the other hand, had Must Bes that included price, comfortable bed, cable/HBO and a swimming pool.

Of these quality characteristics, the manager realized that the hotel was weak in the check-in and express checkout process, and internet hook-up. This Kano model exercise allowed the manager to better address the needs of the customer, based on their Critical to Quality characteristics. Now the work begins to minimize the gap of where the hotel is with respect to where the hotel wants to be.

One final thought: If a characteristic is not on the list, does that mean it can be ignored?

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