You can measure how the performance of the attributes present in your product impact on the degree of satisfaction of its customers? The Kano model has that purpose.
The KANO MODEL
Developed in late 1980, the Kano model provides information about customer satisfaction in relation to the performance of the product or service, making it a powerful tool for quality management. The main function of this model is to determine which attributes are to be incorporated into a product or service and which attributes can be left aside, since it does not add value from the perspective of consumers themselves.
An important feature of the Kano model is the classification of such mandatory attributes, single-dimensional, attractive, reverses and neutral:
Mandatory attributes: are basic criteria of a product; are minimum requirements which are not present or does not reach a certain level of performance will cause dissatisfaction among customers. On the other hand, if these attributes are present or are insufficient, do not result in satisfaction.
Dimensional attributes: customer satisfaction is proportional to the level of performance of the attributes. The higher the level, the greater satisfaction.
Attractions: attributes are those that attract the customer. On the one hand, the presence of these attributes brings a satisfaction more than proportional; on the other hand, the absence does not generate dissatisfaction. Typically, they are not attributes expected by customers.
Reverse: attributes are those which when present, cause only dissatisfaction.
Neutral: attributes are those that do not cause satisfaction and even dissatisfaction.
Figure 1 illustrates the behavior of such classifications.
Figure 1: model of Kano for the attributes of the products and services.
To sort the attributes on these 5 categories, it is necessary to draw up a questionnaire Kano. So, customer is required to answer a couple of questions for each attribute, a question in the form of a question in functional and dysfunctional form according to 5 closed possibilities of response. Through the combination of positive and negative responses, the attribute is sorted in a category. Figure 2 displays the 5 types of response and the result of the combination.
Figure 2: feedback for application of Kano model. Q: questionable: attractive, U: one-dimensional, R: reverse, N: neutral and the: required.
Note that a sixth rank is displayed in Figure 2, called questionable. She suggests that the customer does not understand the question, not fitting in any model category.
The percentage of people who made the proposed combinations in Figure 2 should be compiled in a table. With these values, you can calculate the coefficients of satisfaction and dissatisfaction for each attribute, as the equations in Figure 3. Coefficients close to 1 represent major influence on satisfaction or dissatisfaction, while values close to zero represent little influence.
Note that the coefficients do not take into account the percentage of customers sorted in reverse. Thus, care must be taken in particular in the analysis of this percentage in each attribute.
Finally, plots a graph divided into 4 quadrants with the dividing lines in the coordinates (0; 0.5) and (0.5; 0). The x-axis represents the values for the coefficients of dissatisfaction and the y-axis represents the values for the coefficients of satisfaction. The first quadrant includes the One-dimensional criterion, the second quadrant Appeal criterion, the third quadrant Neutral criteria and the fourth quadrant the Mandatory criterion. Each attribute must be identified in a quadrant of the chart by its values of CS and CI.
We will better understand the functioning of the Kano model through the application in a real case study.
Researchers at the University of Santa Catarina (UFSC) conducted a study to understand the degree of customer satisfaction to the attributes of a restaurant in the State of Rio Grande do Sul. For this, the tool used was the model of Kano.  through a sample calculation according to the demand of the establishment, 146 users were interviewed at random in order to assess 10 atributes:
1. Good Lighting
2. Good Ventilation
3. Cleaning Of Utensils
4. Tables Available
5. Price Of Meal
6. Quality Of Meal
7. Waiting Time For Service
8. Variety Of Menu
9. Beverage quality
10. Credibility and reliability
Customers filled a questionnaire along the lines of the Kano Questionnaire on the way out of the restaurant. Figure 4 shows part of the questionnaire applied, containing the couple of issues (functional and dysfunctional) for the Variety on the menu, as well as the closed opportunities 5. Each of the 10 attributes had this pair of issues, totaling 20 questions to be answered.
Figure 4: part of the questionnaire applied to the Kano model.
For example, the person who answered 1 to the positive Figure 4 question and answer to question 4, considers the attribute Range on the menu as attractive, according to figure 2. Compiling the questionnaires by following this methodology, the researchers have obtained as a result the percentages expressed in Figure 5.
For example, for the Variety of the menu, 20% of respondents were included in the category Attractive, IE, 29 people made the combination of responses to question 1 and 2, 3 or 4 to a negative question.
Com os valores de CS e CI calculados através das equações da Figura 3, plotou-se o gráfico divido em quatro quadrantes, classificando os 10 atributos avaliados em Unidimensional, Atrativo, Neutro ou Obrigatório, conforme a Figura 6.
Figure 5: result obtained through the questionnaire of the Kano model. A: attractive, U: one-dimensional, the: required, N: neutral, R: reverse and Q: questionable. CS: coefficient of satisfaction and IC: coefficient of dissatisfaction.
With the values of CS and CI calculated using the equations in Figure 3, plotou-if the chart divided into four quadrants, sorting the 10 attributes assessed in One-dimensional, attractive, neutral or Required, as shown in Figure 6.
Figure 6: diagram of classification of attributes for the Kano model.
As a result, the Quality attributes of the Drink, good ventilation, quality of Meal, Cleaning utensils, tables available and Credibility and Reliability are classified as single-dimensional, i.e. the larger the presence, the greater the satisfaction. Therefore, the establishment must continuously improve these factors, ensuring greater competitive advantages in the face of its competitors. Already the criteria Range on the menu is the key point to exceed the expectations of customers, since it is rated as Attractive.
The attribute good lighting, being classified as neutral, no impact on satisfaction or customer dissatisfaction. In this way, the restaurant should not prioritize the improvement of ambient lighting. Already the issue Price of the meal, being classified as mandatory, indicates that the higher the value, the greater the dissatisfaction.
Finally, the timeout attribute presents strong inaccuracy in its classification, given that the values of CS and CI correspond to 0.5. This is due to the fact that the percentage of reverse (as shown in Figure 5) is very high, predominating strongly on the other classifications and justifying such inaccuracy. As already mentioned, attributes with a strong predominance of Reverse deserve attention. Therefore, it is concluded that this attribute causes only dissatisfaction, demonstrating the demand for efforts to eliminate it.
References: ROOS, Cristiano; SARTORI, Simone; GODOY, Leoni Pentiado. Modelo de Kano para a identificação de atributos capazes de superar as expectativas do cliente. Revista Produção Online, v. 9, n. 3, 2009.