TRIZ Within the Context of The Kano Model or Adding the Third Dimension to Quality
Editor | On 23, Oct 1999
Steve Ungvari, SPI, Inc.
The purpose of this paper is to link the evolution of quality with the emerging body of knowledge contained in the TRIZ methodology. Understanding how TRIZ integrates with quality will arm the reader with a more potent approach to successfully competing in the marketplace. Author’s Note: Writing this paper was precipitated by Dr. Kano’s expression of interest in TRIZ in his discussions with Bou Bertsch of Ideation International in the Netherlands.
The notion of inherent quality, of products and services that are deemed to be superior as opposed to inferior, has been discussed and debated for centuries. Philosophers such as Aristotle, Rene Descartes and John Locke have provided different facets of the definition of quality.
In the 1930s, Dr. Walter A. Shewhart began developing his definition of quality through the use of statistics and what is now termed “Statistical Quality Control.” During and after World War II, the statistical variations on the meaning of quality continued in the United States and Japan with the work of W.E. Deming, Joseph Juran and Armand V. Feigenbaum. In Japan, the work of Kaoru Ishikawa, Shigeru Mizuno, Shoji Shiba, Yoji Akao and Genechi Taguchi provided additional perspectives and a much larger context in which quality is germane, e.g., “Total Quality Management (TQM)” and “Loss to Society.”
The Kano Model
In the late 1970s Dr. Noriaki Kano of Tokyo Rika University further refined the notion of quality derived partially from his study of Herzberg’s “Motivator-Hygiene Theory.” Whereas many of the previous definitions of quality were linear and one dimensional in nature, i.e., good or bad, small versus large loss to society, Dr. Kano integrated quality along two dimensions. The two dimensions were: 1) The degree to which a product or service performs, and 2) The degree to which the user is satisfied. See Figure 1.
The juxtaposing of the quality parameters of performance and user satisfaction in a two-axis plot created the ability to define quality in a more sophisticated and holistic manner. The correlation of quality on two axes led Dr. Kano to three unique definitions of quality, namely: Basic Quality, Performance Quality and Excitement Quality. See Figure 2.
The Three Types of Quality
The Kano Model is very useful in providing a level of sophistication not available in a one-dimensional model of quality. If the level of customer satisfaction is plotted on a vertical axis, and the degree that the product or service has achieved a given performance attribute on the horizontal axis, different types of customer wants and needs can be shown to cause widely different responses. The model shows that the customer’s responses can be classified into three types as shown in Figure 2 above, i.e., Basic, Performance and Excitement.
The dynamics of Basic Quality indicate that some customer requirements, if not achieved. cause high dissatisfaction, and, if they are achieved, have only a limited effect on causing customer satisfaction. The reason for this is that this quality type isexpected by the customer. For example, when going into a restaurant for a meal, the customer expects there to be a place setting. If there isn’t one, the customer will be dissatisfied. If there is a place setting, no credit will be given because there is supposed to be one. On the other hand, having many place settings does not create any additional satisfaction.
In the Automotive world, the customer expects a vehicle to start easily, provide a safe driving environment, and be free of squeaks, rattles and wind noise. Satisfaction is not created if a vehicle does these things. However, if these “basic” needs are not met, the result is devastating to the reputation and business of the Original Equipment Manufacturer. Basic quality provides “down-side risk” with very little “up-side potential” for customer satisfaction.
Customers will express violation of basic quality attributes by complaining. In industry, basic quality is typically measured by customer complaints, warranty data, product recalls, number of lawsuits, things-gone-wrong (TGW) and other failure reports.
A second type of customer requirement generates satisfaction proportional to the performance of the product. This quality type is referred to as Performance Quality. Performance quality attributes generally cause a linear response. Increased levels of satisfaction are caused by increased levels of achievement. The customer in a restaurant expects his/her order to be taken promptly and accurately and the food delivered in a reasonable period of time. The better the restaurant meets these needs, the more satisfied he/she is.
Customers freely express their desires relative to performance quality when they are asked. This type of information is often called the Voice of the Customer, because these are the types of things that customers like to talk about. They want the car to perform one way or another, and have this or that feature. We measure them using customer research tools, feature rating surveys and ride/drive evaluations, asking how well a product performs relative to a graduated scale.
An automotive customer expects a vehicle to have good engine performance, but performance is gauged relative to expectations. Someone that is buying a small economy car will not expect the same raw performance as they would in a “muscle” car. Generally speaking, however, the better the performance, the greater the satisfaction.
The third quality type generates positive satisfaction at any level of execution. This is referred to as Excitement Quality. Excitement is generated because the customer received some feature or attribute that they did not expect, ask for, or even think was possible. For example, if the restaurant provides a glass of champagne “on the house,” the customer will be pleasantly surprised. Likewise, the customer of a vehicle may not expect a car to have a built-in global positioning system, a maintenance-free battery, heated seats, etc., but will be pleased when they are discovered during the ownership experience.
Customers generally do not articulate excitement attributes in customer surveys, because they do not know that they want them. In order to generate customer excitement and brand loyalty, companies must leverage their creative resources to identify ideas and innovations that cause customer excitement. Excitement quality becomes the special reason why customers will make a specific company the default choice over the competition and return to buy again and again.
Excitement attributes cause an exponential response. Small improvements in providing excitement items cause relatively large increases in satisfaction. Several small excitement features may accumulate and generate sheer delight on the part of customers.
The Kano model is useful for providing a two-dimensional model of quality. In actual application, requirements do not always fall neatly into one of the three categories. Very high levels of performance relative to expectations can act like excitement attributes and provide real reasons to choose a particular product over its competitor. Likewise, an intended excitement feature executed badly will cause dissatisfaction.
Customer Requirements Over Time
It has also been observed that customersâ€™ requirements change over time. Sources of excitement when they were first introduced tend to become expected as the market becomes familiar and saturated with them. In time, excitement quality will become a performance item, and, with the passage of time, quite possibly a basic requirement.
Automatic transmissions which initially provided excitement because they made cars much easier to drive are classified today as a basic quality item. For a time, customers made comparisons because some designs performed better than others, but, in today’s vehicles, customers demand that automatic transmissions perform flawlessly. Customers talk about them only if there is a problem. Figure 3 shows the dynamic of time.
There is no doubt that to be competitive, products or services must flawlessly execute all three quality types. Meeting customersâ€™ basic quality needs provides the foundation for the elimination of dissatisfaction and complaints. Exceeding customersâ€™ performance expectations creates a competitive advantage, and innovations differentiating the product and the organization creates an excited customer.
TRIZ and the Archeological Analog
TRIZ, the Russian language acronym for the Theory of Inventive Problem Solving, is the product of an exhaustive analysis of the world’s most creative inventions as described primarily in patent literature. The analysis of some three million inventions over the past fifty years can be compared to an archeological reconstruction of life forms as recorded in the fossil record. In a sense, one can think of TRIZ as an encapsulation of the historical record of the evolution of product quality. TRIZ theory, as in archeology, is a product of the cataloguing and analysis of empirical data. As an archeologist probes the remains of the fossil record, they seek to understand what natural phenomena led to the emergence of newer and better (higher-quality) life forms. In a similar fashion, Genrich Altshuller observing the “natural” quality progression of products, discovered a series of repeatable patterns he called The Laws of Technological Systems Evolution. In other words, just as natural forces have been discovered to produce higher-quality life forms, the analog of how technological systems evolve was uncovered by the extensive analytical work of Altshuller and his colleagues.
There are several significant differences between archeological reconstruction and TRIZ. In archeology, much of the record is not complete enough to allow for unassailable conclusions. The archeological records also contain large chronological gaps making it impossible to extrapolate vectors of evolution. This is clearly not the case with TRIZ. In TRIZ, there is a complete record making reconstruction of systems evolution clear to the point of predictability.
Adding the Third Dimension to Quality
The two dimensional model of quality, as described by Kano, is itself proof of how systems (any system) evolves. One of the laws of systems evolution is the Law of Dynamicity. This law states that any system will become more flexible and dynamic over time. Another law states that single (mono) systems will combine with other mono systems to form new “bi-systems.” The conjoining of Quality and TRIZ is an example of this law.
The advantage of a bi-system is that it provides additional functionality with increased efficiency and less consumption of resources as opposed to separate mono systems. This is precisely the rationale for combining Quality, as expressed in the Kano Model, and TRIZ into a powerful three dimensional bi-system as shown in Figure 4.
Just as the Kano Model is composed of three elements, the TRIZ interface is likewise composed of three separate but complementary subsets including: 1) Anticipatory Failure Determination1 (AFD), 2) Classical TRIZ Problem-Solving Tools, and Directed Evolution2 (DE). Anticipatory Failure Determination and Directed Evolution are the latest additions to the TRIZ “toolbox.” Both AFD and DE have been developed through the Kishinev School under the leadership of Boris Zlotin and Alla Zusman. The classical tools of TRIZ are the product of Altshuller’s patent work from 1946 to 1985.
The third dimension to quality made possible by TRIZ provides organizations with powerful tools to fully leverage each of the three quality types. As important as it is to understand each of the three quality types, it is equally important to be able to take specific actions on the unique challenges posed be each type. The three TRIZ tools provide the quality professionals with the ability to explore, improve and optimize the full technological solution space for each quality type.
Basic Quality and AFD
The Basic Quality dimension on the Kano Model addresses features or functions that are “demanded,” yet unspoken. While this may sound contradictory, it is because basic quality is deemed to be so obvious that articulation of it seems pointless. Basic Quality, however, is a disaster waiting to happen. A customer of an automobile would not specify that they want fuel tanks that do not explode. An engineer would never deliberately design a fuel tank to explode. Recent history, however, from the Ford Pinto, the GM Light Truck side-saddle fuel tanks to the Chevrolet Malibu rear-end $4.9 billion-dollar judgment vividly exemplify that Basic Quality is repeatedly violated and the consequences that follow when it is.
How can engineers, within the context of product development, do a better job of designing out these devastatingly inherent flaws? Paradoxically, violations of Basic Quality can be prevented by proactively exploring every conceivable method to create such failures. It is this bit of logic that makes AFD fundamentally different in approaching the elimination of failure modes.
Traditional failure prediction tools such as Failure Mode & Effects Analysis (FMEA), Fault Tree Analysis (FTA) and Hazards and Operations Analysis (HAZOP) are predicated on answering the question: “What can go wrong?” In these traditional methods, since the point of departure is a conceptualized articulation of the current system, the process follows traditional failure scenarios. This logic is lacking structural validity because it is subject to Psychological Inertia (PI). An engineer will analyze a situation only from his or her known paradigm. The constraints of the engineers paradigm will limit the failure analysis to something less than 100% of the available catastrophe space.
AFD, on the other hand, inverts the situation by asking the question: “How can I destroy the system?” This question presents an “inverted” problem as well as an “inventive” one. There are two distinct benefits from this inverted approach. First, viewing the system with the intent to destroy it provides a fresh analytical perspective, and second, it makes the problem “inventive,” thereby bringing to bear the full arsenal of TRIZ tools and techniques. The application of all of the TRIZ tools eliminates Psychological Inertia ensuring a thorough rigorous analysis of potential violations of Basic Quality.
Performance Quality and Classical TRIZ
As the name implies, Performance Quality is characterized by the ability of the product to meet desired levels of achievement. Performance Quality is also characterized by the fact that the user defines the level of “goodness” that is desired. The advantage to the quality professional in dealing with performance issues is that a series of metrics can be established to keep score.
Given the linear nature of performance quality, it is axiomatic that achieving higher levels of performance, especially in a cost effective way, will create product differentiation and competitive advantage. Understanding how to overcome the barriers to low-cost performance increases is the key to moving the performance index ahead of the competition.
Product performance is limited, to a great extent, by inherent system conflicts that act as barriers to increasing performance levels. A typical conflict, for example, is weight versus strength. In TRIZ terms, this is called a Technical Contradiction. The essence of the contradiction is that to increase strength, the typical way of accomplishing that is to increase the weight of the object. Increased weight, however, is undesirable as is reduced strength. These conflicts are usually resolved by meeting the conflicting parameters “halfway,” vis a’ vis, a compromise solution.
The classical tools of TRIZ, including the 40 Inventive Principles, the Contradiction Matrix, Substance-Field Modeling, Standard Solutions, the Algorithm for Inventive Problem Solving (ARIZ), and Effects (physical chemical and geometrical) plus the modern tools developed since 1985 including Problem Formulation3 and the System of Operators4 are uniquely designed to tackle the issue of elimination of system conflicts. To return to the previously mentioned conflict, it is obvious that if strength can be increased without paying a weight penalty, the product would possess advantages over competitive alternatives. This has been accomplished by use of composite materials, honeycomb structures, etc.
It is beyond the scope of this short article to explain all of the TRIZ tools mentioned above as there are volumes of printed matter written to accomplish that. Suffice it to say that the classical TRIZ problem-solving tools will enable the quality, engineering and product development professional with the elimination of inherent system conflicts in a cost-effective way. When this is accomplished, the result is increased cost-effective performance and greater customer satisfaction.
Excitement Quality and Directed Evolution
Excitement Quality addresses what are termed as “latent” or unmet user needs. These needs are latent because users are not consciously aware of their need. Users will oftentimes resort to “workarounds,” oblivious to the fact that the product does not fully meet all of their needs. When a user discovers an excitement feature, they are pleasantly surprised and even delighted. Within the context of the Kano Model, excitement features provide the greatest opportunity to differentiate the product.
The TRIZ interface to produce dimensional depth to Excitement Quality is Directed Evolution. Directed Evolution is itself the latest derivative of Technological Forecasting. Technological Forecasting is a TRIZ capability because of Altshuller’s discovery of the Laws of Technological Evolution. These eight laws represent repeatable patterns depicting the natural progression of products through Life Cycle “S-curves.” Through the efforts of Zlotin, Zusman and others, additional gradations to these laws have been provided called “lines of evolution.” For each major law, there are a number of lines that refine and pinpoint the understanding of the evolutionary life cycle progression. The lines of evolution allow organizations insights into future product derivatives. These derivatives will occur “naturally” over time or they can be “directed” to appear as a part of an organizationâ€™s product development strategy.
For example, the law of Dynamicity indicates that systems will become flexible and dynamic over time. A well-known example of this law is the Snake LightÃ¤Ã¤ introduced several years ago by Black & Decker. The Snake LightÃ¤Ã¤ proved so popular that Black & Decker couldn’t produce them fast enough. This product derivative was totally predictable well before it was ever conceptualized. Had a competitor known about Directed Evolution and introduced the product before it was naturally conceived by Black & Decker, they, and not Black & Decker, would have reaped the goodwill and financial benefits.
The power of Directed Evolution is the ability of an organization to predict the full spectrum of future product scenarios and then to select the most promising one. Having done that, it is possible to create a technological roadmap and establish patent fences to protect a companyâ€™s intellectual property and future income stream.
The understanding of Quality has progressed over the years into a more sophisticated model integrating product performance with customer satisfaction. This two-dimensional model provides the foundation for a three-dimensional model making it possible to utilize powerful invention-based tools to explore, understand and exploit the entire product possibility space.
TRIZ, like the archeological record, provides an encapsulated view of how and why products evolve into more robust derivatives. Competency in the complete TRIZ tool-set makes it possible to foresee potential catastrophic failures, be able to eliminate inherent system contradictions, and direct future new product derivatives to address latent requirements.
The Kano Model, coupled with the TRIZ interface, represents the most complete and powerful conceptualization of the quality dynamic and the scientific ability to exploit it.
The author wishes to acknowledge the invaluable contribution of the following individuals:
Mr. Zion Bar-El, President and CEO of Ideation International for challenging me to write this article
Ms. Alla Zusman, Ms. Karen Pike, Mr. Boris Zlotin, Mr. Dana Clarke, and Dr. Stan Kaplan for their editorial comments