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Kano model lectura_1

  1. 1. The Refined Kano’s Model and its Application CHING-CHOW YANG Chung-Yuan Christian University, Taiwan, Republic of China ABSTRACT Kano’s model of five categories of quality attributes – attractive, one-dimensional, must-be, indifferent, and reverse quality – is widely used by industries and researchers. However, the model has a deficiency that prevents firms from precisely evaluating the influences of quality attributes. The weakness is a failure to take account of the degree of importance accorded to certain quality elements by customers. Kano’s model can be refined. The present study adds the importance of quality attributes and, in so doing, the refined model divides Kano’s first four categories into eight categories – highly attractive and less attractive, high value-added and low value-added, critical and necessary, and potential and care-free. Based on the refined model, firms can obtain a more accurate understanding of the quality attributes from the customer’s perspective, and can thus make more precise quality decisions. In addition to modifying Kano’s model, the present study also develops an importance–satisfaction (I–S) model. By integrating the refined Kano’s model and the I–S model firms can gather even more valuable information on quality decisions. The refined Kano’s model and the I–S model are illustrated with a case study. KEY WORDS: Kano’s model, importance–satisfaction model, highly attractive attribute, high value-added attribute, critical attribute Introduction To sustain competitiveness and long-term profitability, companies devote themselves not only to the attraction of new customers, but also to the retention of old customers with a view to a continuing business relationship through incremental increases in purchases and the maintenance of customer loyalty (Gorst et al., 1998). Several studies have demon- strated that high loyalty and customer retention are associated with increased intention of future purchases (Eklof & Westlund, 1998), and that customer loyalty is dependent on the customer’s perception of the quality of the goods or services provided (Gorst et al., 1998; Sirohi et al., 1998). Industries therefore pursue quality in product and service in order to satisfy their customers. Total Quality Management Vol. 16, No. 10, 1127–1137, December 2005 Correspondence Address: Ching-Chow Yang, Department of Industrial Engineering, Chung-Yuan Christian University, Taiwan, Republic of China. Email: chinchow@cycu.edu.tw 1478-3363 Print=1478-3371 Online=05=101127–11 # 2005 Taylor & Francis DOI: 10.1080=14783360500235850
  2. 2. In the past two decades, industries have implemented a range of quality management systems and standards, such as QCC, ISO 9000, TQM, and so on. The aims of these quality activities are to achieve customer satisfaction (Kano et al., 1996; Kondo, 2001) and to win their long-term trust by creating products and supplying services that fulfil customer requirements and exceed their expectations. Indeed, the pursuit of customer satisfaction and loyalty should be the main concern of all companies (Gorst et al., 1998). In the past, customer satisfaction has been perceived in one-dimensional terms – the greater the fulfilment of desired quality attributes, the higher would be customer satis- faction. However, there are some quality attributes that fulfil individual customer expec- tations to a great extent without necessarily implying a higher level of customer satisfaction (Matzler & Hinterhuber, 1998). Several studies have therefore attempted to link the physical and psychological aspects of quality to see how specific attributes of a product or service actually relate to customer satisfaction or dissatisfaction, where the physical aspect is concerned with the physical state or extent of the specific attributes, and the psychological aspect is related to the customer’s subjective response in terms of personal satisfaction (Schvaneveldt et al., 1991). Similarly, Kano et al. (1984) considered two aspects of any given quality attribute – an objective aspect involving the fulfilment of quality and a subjective aspect involving the customers’ perception of satisfaction. Kano’s model is illustrated in Figure 1. Using this model, quality attributes can be divided into five categories as follows: . attractive quality attribute: an attribute that gives satisfaction if present, but that produces no dissatisfaction if absent; . one-dimensional quality attribute: an attribute that is positively and linearly related to customer satisfaction – that is, the greater the degree of fulfilment of the attribute, the greater the degree of customer satisfaction; Figure 1. Kano’s model of quality attributes 1128 C.-C. Yang
  3. 3. . must-be quality attribute: an attribute whose absence will result in customer dissatis- faction, but whose presence does not significantly contribute to customer satisfaction; . indifferent quality attribute: an attribute whose presence or absence does not cause any satisfaction or dissatisfaction to customers; and . reverse quality attribute: an attribute whose presence causes customer dissatisfaction, and whose absence results in customer satisfaction. Questionnaire surveys of customers can be used to categorize quality attributes (Kano et al., 1984; Bolster et al., 1993). Once quality attributes are categorized, products and services can be designed to meet the different requirements for each quality attribute, according to its category. It is critical to identify must-be quality attributes and to meet demand for these at a minimum threshold level at least. Firms must also do their best on the one-dimensional attributes – which are typically articulated by customers as being a functionality they would desire. The attractive quality attributes can be selected as competitive weapons to draw the attention of customers, especially new customers (Rao et al., 1997). Using Kano’s model, quality attributes that have the greatest influence on customer satisfaction can therefore be identified, and these can then be used to focus on priorities for product or service development and improvement (Hinterhuber et al., 1997; Matzler & Hinterhuber, 1998). Several researchers have studied Kano’s model. Kano et al. (1984) empirically con- firmed the applicability of their model for quality attributes of television product and other manufactured goods. Miyakawa & Wong (1989) studied Kano’s model in manufac- tured goods. Schvaneveldt et al. (1991) explored the applicability of Kano’s model to four mass-market services – retail banking, cleaning services, family restaurants, and super- markets. Matzler & Hinterhuber (1998) demonstrated the applicability of Kano’s model, in combination with quality function deployment, using a case study from the ski industry. Sa Moura & Saraiva (2001) used Kano’s analysis to develop an ideal kindergarten. The Refined Kano’s Model The most useful applications of Kano’s model are in the area of product and service devel- opment and improvement. However, trade-offs are sometimes necessary. If two product requirements cannot be met simultaneously for technical or financial reasons, firms must consider the criteria that have the greatest influence on customer satisfaction (Matzler & Hinterhuber, 1998). Usually, for any quality attribute, its influence on custo- mer satisfaction is closely related to the degree of importance attached to it by customers (Kristensen et al., 1992). For example, in a car, an automatic gearbox and a luggage carrier are both attractive quality requirements. However, most customers consider an automatic gearbox to be more important than a luggage carrier. Therefore, adding an automatic gearbox will create greater customer satisfaction than adding a luggage carrier. Kano’s model can therefore be refined by taking into account the importance of certain quality attributes. With respect to the must-be quality attributes, if such a quality attribute is also found to have high importance in the estimation of customers, this quality attribute is not only a necessary quality requirement but also a critical quality requirement. In contrast, if a must-be quality attribute is considered less important, it can be defined as a necessary quality requirement, but without being considered critical. The Refined Kano’s Model and its Application 1129
  4. 4. With respect to one-dimensional quality attributes, increasing such attributes will raise customer satisfaction. A one-dimensional quality attribute is therefore a value-added quality attribute. It is therefore possible to define some one-dimensional quality attributes with high importance as high value-added quality attributes, whereas others can be classed as low value-added attributes. For the attractive quality attributes, those with high importance can be classified as highly attractive quality attributes, whereas those of lesser importance can be classified as less attractive quality attributes. The indifferent quality attributes are referred to in this study as care-free quality attri- butes. However, if an indifferent quality attribute does possess higher importance than another, it can be defined as a potential quality attribute because it does have some poten- tial to attract customers. The indifferent quality attributes can therefore be classed as care- free or potential, depending on their degree of importance. Table 1 lists the redefined categories of quality attributes obtained by refining Kano’s model. In Figure 2, curves are used to illustrate the means of the redefinitions of quality attributes. Table 1. Categories of quality attributes in unrefined and refined Kano’s model Categories of quality attributes in Kano’s model Categories of quality attributes with high importance in refined model Categories of quality attributes with low importance in refined model Attractive Highly attractive Less attractive One-dimensional High value-added Low value-added Must be Critical Necessary Indifferent Potential Care-free Figure 2. Refined Kano’s model of quality attributes 1130 C.-C. Yang
  5. 5. The redefinitions of the categories of quality attributes according to the refined model allow firms to make quality decisions with more precision. The following descriptions illustrate the application of the refined model. 1. Kano’s attractive attributes Highly attractive quality attributes These are good weapons for firms to attract potential customers. These represent strategic attribute offerings. Less attractive quality attributes Because these have little attraction to customers, these quality attributes can be discarded if cost considerations demand this. 2. Kano’s one-dimensional attributes High-value-added quality attributes These make a high contribution to customers’ satisfaction. They therefore can lead to increased revenue. Firms should therefore make efforts to provide such attributes to customers. Low value-added quality attribute These attributes make less contribution to customer satisfaction. But firms cannot afford to ignore these attributes. The firms also need to avoid providing too less level of these attributes to dissatisfied customers. 3. Kano’s must be quality attributes Critical quality attributes These are essential to customers. Firms must provide sufficient fulfilment of these attributes to customers. Necessary quality attributes Firms can meet these at a required level to avoid dissatisfying customers. 4. Kano’s indifferent quality attributes Potential quality attributes These attributes will gradually be coming the attractive attributes. Firms can consider providing these as strategic weapons to attract customers in the future. Care-free quality attributes If necessary, firms need not offer these attributes in view of cost considerations. These brief descriptions demonstrate how the refined Kano’s model can help firms make accurate decisions on quality planning. Applications A Practical Example of the Refined Model The author has conducted several kinds of surveys for many companies, one of which is a home-appliance manufacturer. The survey for this company covered the product quality of various goods including an air-conditioner, a refrigerator, a washing machine, and a television, together with service quality associated with these products. In this article, the example of the air-conditioner is used for further discussion of the application of the refined Kano’s model. The Refined Kano’s Model and its Application 1131
  6. 6. A total of 20 key customers were first interviewed, including the end users and the consignees of these home appliances. At the same time, the nominal group method was used to conduct two panel discussions. The participants included service personnel, sales personnel, and the supervisors from the quality-assurance division and sales division. The purpose of customer interviews and internal panel discussion was to determine the quality attributes to be contained in the questionnaire. As a result, 24 quality attributes of the air-conditioner were developed for study. Three kinds of questionnaires were designed: . the importance of quality attributes; . the satisfaction of quality attributes; and . the categorization of attributes according to Kano’s model. For the first two surveys, Likert-type 5 scales were used. For the study of Kano’s model, the method suggested by Kano et al. (1984) was used to design the questionnaire. The questionnaires were mailed out to 1400 customers randomly and 150 valid questionnaires were returned. The 24 quality attributes are listed in Table 2. The degrees of importance were assessed into two categories – ‘high’ importance if the degree of importance was greater than the mean for the 24 quality attributes, and ‘low’ if below the mean. This allowed classification of the categories according to the refined Kano’s model (see sixth column of Table 2). (The final column in Table 2 – the ‘category in the I–S model’ – is explained later in this paper.) The first 12 attributes are above the mean and are therefore classed as being of ‘high importance’. Most of these attributes are one-dimensional, due to the features of these attributes. As with all one-dimensional attributes, the greater the extent of this attribute, the greater the customer perception of satisfaction. According to the refined model, these one-dimensional attributes of high importance are categorized as high value- added. Of the first 12 attributes, only three belonged to the must-be category. They are redefined in the refined model as critical attributes. Among the attributes of lesser importance (numbers 13 to 24 in Table 2), five are one- dimensional, and are therefore redefined as low value-added attributes in the refined model. There are four attractive attributes, and these are therefore re-categorized as less attractive attributes. Only one must-be attribute with low importance is identified in this research. This becomes a necessary attribute in the refined model. There are two attributes identified as indifferent, now categorized as care-free attributes according to the refined model. It is not difficult to understand that one-dimensional attributes and attractive attributes can be ranked as being of high importance or low importance. The situation with must-be attributes is not as obvious. It might seem that these should all be of high importance. Indeed, most of those must-be attributes are of high importance – but not all. It is possible for an attribute to be required, but still not rank highly in overall importance to consumers. In the present research, only one attribute (the guard net for the fin of the air-conditioner) was classified as being necessary (that is, must-be, but with low importance). The advantage of the refined model over the unrefined Kano’s model is shown by the following example. The attributes ‘compressor noise’ and ‘free wind control and auto- louver function’ are both categorized as one-dimensional attributes according to the 1132 C.-C. Yang
  7. 7. Table 2. Air-conditioner quality attributes Ranking Quality attribute Importance (mean) Satisfaction (mean) Category in Kano’s model Category in refined Kano’s model Category in I–S model 1 Compressor noise 4.46 3.46 One-dimensional High value-added To be improved 2 Durability of fan motor 4.33 3.88 One-dimensional High value-added Excellent 3 Outlet noise of air-conditioner 4.33 3.54 One-dimensional High value-added To be improved 4 Anti-erosion of heat exchanger 4.32 3.76 One-dimensional High value-added Excellent 5 Stainless base 4.15 3.90 Must-be Critical Excellent 6 Ease of maintenance and cleaning 4.07 3.75 One-dimensional High value-added Excellent 7 Comfort 4.06 3.72 One-dimensional High value-added Excellent 8 Air-cleaning efficiency 4.04 3.65 One-dimensional High value-added To be improved 9 Temperature display (room and setting) 4.02 3.87 Must-be Critical Excellent 10 Drop protection and drainage 3.97 3.75 One-dimensional High value-added Excellent 11 Inverter compressor 3.95 3.63 Must-be Critical To be improved 12 Negative ions 3.95 3.76 Attractive Highly attractive Excellent 13 Price 3.94 3.40 One-dimensional Low value-added Care-free 14 Material accordance of base and internal compressor surrounding 3.93 3.71 Attractive Less attractive Surplus 15 Free wind control and auto louver function 3.92 3.65 One-dimensional Low value-added Care-free 16 Cleaning instructions 3.92 3.54 Attractive Less attractive Care-free 17 Guard net for fin 3.86 3.79 Must-be Necessary Surplus 18 Ease of portability and installation 3.80 3.65 One-dimensional Low value-added Care-free 19 Attractiveness and design for external looks 3.77 3.73 One-dimensional Low value-added Surplus 20 Wired and wireless control function 3.68 3.77 Attractive Less Attractive Surplus 21 Four key functions in one 3.64 3.60 Attractive Less attractive Care-free 22 Universal remote control 3.57 3.65 Indifferent Care-free Care-free 23 Cleanliness of surface 3.56 3.66 One-dimensional Low value-added Care-free 24 Pre-order function of starting time 3.35 3.55 Indifferent Care-free Care-free Mean 3.941 3.678 Note: Ranking is according to level of importance. If two or more attributes have the same importance level, the attribute with a smaller deviation is ranked higher. TheRefinedKano’sModelanditsApplication1133
  8. 8. rules of Kano’s model. According to the unrefined model, a firm will pay similar attention to these two attributes. However, when the firm recognizes the categories of these attri- butes according to the refined model, the ‘compressor noise’ attribute is seen to be a high value-added attribute (and therefore of greater significance to the firm), whereas the ‘wind control and auto-louver function’ is of low value-added (and therefore of lesser importance to the firm). As a result, the firm will adopt very different strategies towards the two attributes. Business management normally focuses on improvements to quality elements that are unsatisfactory in the estimation of customers. However, according to the refined model, this is not the only consideration. Firms can simultaneously take care of the satisfaction level of quality attributes and their degree of importance. Firms can thus obtain much valu- able information for improvements from a comparison between the satisfaction levels and the degree of importance of quality attributes. This is a very important concept, since cus- tomers evaluate quality by using quality attributes that they recognize as important (Deming, 1986; King, 1987; Headley & Choi, 1992). If customers’ satisfaction on these important attributes falls to a low level, the overall quality evaluation from customers can be very poor. Therefore, those quality attributes which customers consider to be highly important and which have a lower satisfaction level are those that management needs to address as a first priority for improvements. The Importance–Satisfaction Model The above discussion leads to the development of a model referred to as the importance– satisfaction model (I–S Model) (Yang, 2003). This is illustrated in Figure 3. In this model, the horizontal dimension shows the degree of importance of a quality attribute, and the vertical dimension shows the satisfaction level of the quality attribute. The order pair (importance scale, satisfaction scale) can then be located on the Figure 3. The importance–satisfaction model 1134 C.-C. Yang
  9. 9. coordinates. The means of the importance scale and the satisfaction scale can be used to divide the coordinate into four areas, as follows: . I. Excellent area: The attributes located in this area are those that customers considered to be important, and for which the performance is satisfactory to customers. Retention of customers requires that performance in these attributes be continued. . II. To be improved area: The quality attributes listed in this area are those considered as important to customers but for which the performances have not met with expectation. The company must focus on these attributes and make improvements immediately. . III. Surplus area: The attributes listed in this area are not very important to customers, but the perceptions of customers are quite satisfactory. The company can put these quality attributes aside. If the company needs to cut costs, these are the attributes that can be eliminated without incurring a significant negative impact on the customer satisfaction. . IV. Care-free area: These quality attributes are those about which customers have a lower satisfaction level, but which they also rank as being less important. The company does not need to worry about these attributes, because these items have less impact on the whole quality-evaluation process. Even though this importance–satisfaction model is a simple structure, it can neverthe- less provide much useful information about a company’s quality performance. The model can be applied to the empirical study described above. The last column of Table 2 shows the I–S category for each of the quality attributes discussed in the empirical study. The results are displayed in Figure 4. Figure 4. The display of the I–S model for Table 2 The Refined Kano’s Model and its Application 1135
  10. 10. From the data in Table 2 and the display of Figure 4, much valuable information can be obtained. The important points to be noted are as follows. . Most of the must-be quality attributes are found to be important, but not all. The attri- bute dealing with the guard for the fin of the air conditioner is treated as must-be, but it is not considered to be important. It is therefore classified as a necessary attribute. . For one-dimensional attributes and attractive attributes, some are considered to be important and some are not. . In the to be improved area, three attributes are high value-added, but only one attribute is critical. . Although the attribute dealing with the price of the air-conditioner is located in the care- free area, it is very close to the to be improved area. As a result, the company must still pay attention to this attribute. . There are three critical attributes – two are located in the excellent area. This means that company has ascertained the critical nature of these attributes, and has also pro- vided them to a sufficient extent. . There is one highly attractive attribute that is located in the excellent area. This is the attribute relating to ‘negative ions’. This therefore represents a very good competitive weapon. It is of interest that the company has also emphasized the importance of this point in its advertising. . There are two less attractive attributes (denoted by numbers 14 and 20 in Table 2) that are located in the surplus area. If the company wants to reduce costs, these attributes can be considered. . There are only two indifferent attributes (denoted by numbers 22 and 24). These are listed in the care-free area, they are also identified as care-free attributes in the refined model, and therefore the company has no need to pay much attention to these two attributes. Analyses of this type are very useful and valuable for the company. The company can make better decisions with respect to product quality by referring to the models presented here. Conclusion Kano’s model is a good tool for industries to use in analysing key quality attributes in order to make better decisions on quality strategies. But the unrefined model has a deficiency in that the degree of importance of quality attributes is neglected. Customers are the only judges of quality in goods and services, and they evaluate the quality by using several attributes that are important from their perspective. Thus, degree of import- ance is a critical dimension considered by customers when they are evaluating the quality performance. On this basis, the present study has integrated this ‘importance’ concept into Kano’s model – thus developing a new refined model. According to the refined Kano’s model, quality attributes can be divided into more precise categories. An increasing number of companies conduct surveys of customers. It is the contention of this paper that firms can analyse the categories of quality attributes according to both the refined Kano’s model and the I–S model. This enables firms to obtain much more valuable 1136 C.-C. Yang
  11. 11. information. The refined Kano’s model is not only a useful practical tool for industries, but it is also a theoretical model for academic research. References Berger, C. et al. (1992) Kano’s methods for understanding customer – defined quality, Center for Quality Management Journal, (fall), pp. 3–35. Deming, W. E. (1986) Out of Crisis (Cambridge, MA: MIT Press). Eklof, J. A. & Westlund, A. (1998) Customer satisfaction index and its role in quality management, Total Quality Management, 9(4&5), pp. 80–85. Gorst, J. et al. (1998) Providing customer satisfaction, Total Quality Management, 9(4&5), pp. 100–103. Headley, D. E. & Choi, C. (1992) Achieving service quality through gap analysis and a basic statistical approach, The Journal of Services Marketing, 6(1), pp. 5–14. Hinterhuber, H. H. et al. (1997) Un modello semiqualitative per la valutazione della soddisfazione del cliente, Micro and Macro Marketing. (April), pp. 127–143. Kano, N. et al. (1984) Attractive quality and must-be quality, Journal of Japanese Society for Quality Control, 14(2), pp. 38–48 (in Japanese). Kano, N. et al. (1996) Attractive quality and must-be quality, The Best on Quality, 7 (Milwaukee, WI: ASQC Quality Press). King, C. A. (1987) A framework for a service quality assurance system, Quality Progress (September), pp. 27–32. Kondo, Y. (2001) Customer satisfaction: how can I measure it?, Total Quality Management, 12(7&8), pp. 867–872. Kristensen, K. et al. (1992) On measurement of customer satisfaction, Total Quality Management, 3(2), pp. 123– 128. Matzler, K. & Hinterhuber, H. H. (1998) How to make product development projects more successful by integrating Kano’s model of customer satisfaction into quality function deployment, Technovation, 18(1), pp. 25–37. Miyakawa, M. & Wong, C. K. (1989) Analysis of attractive quality and must-be quality through product expectation factors, Proceedings of 35th Technical Conference, Japan Society for Quality Control, Tokyo, pp. 101–104. Rao, S. S. et al. (1997) Does ISO 9000 have an effect on quality management practices? An empirical study, Total Quality Management, 8(6), pp. 335–346. Sa Moura, P. & Saraiva, P. (2001) The development of an ideal kindergarten through concept engineering/quality function deployment, Total Quality Management, 12(3), pp. 365–372. Schvaneveldt, S. J. et al. (1991) Consumer evaluation perspectives of service quality: evaluation factors and two- way model of quality, Total Quality Management, 2(2), pp. 149–161. Sirohi, N. et al. (1998) A model of customer perception and store loyalty intentions for a supermarket retailer, Journal of Retailing, 74, pp. 223–245. Yang, C. C. (2003) Establishment and applications of the integrated model of service quality measurement, Managing Service Quality, 13(4), pp. 310–324. The Refined Kano’s Model and its Application 1137