Within the Context of The Kano Model
Adding the Third Dimension to Quality
The purpose of this
paper is to link the evolution of quality with the emerging body of
knowledge contained in TRIZ methodology. Understanding how TRIZ integrates
with quality will arm the reader with a more potent approach to
successfully competing in the marketplace.
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. 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.
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."
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.
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,
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 is expected 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
In the Automotive
world, the customer expects a vehicle to start easily provide a safe
driving environment, be free of squeaks, rattles and wind noise.
Satisfaction is not created if a vehicle does these things. The result if
these "basic" needs are not met, however, 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.
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
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 their order to
be taken promptly, accurately and the food delivered in a reasonable
period of time. The better the restaurant meets these needs, the more
satisfied he/she is.
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 feature or
that. 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.
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 it was possible. If the restaurant, for example,
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.
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
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.
Requirements Over Time
It has also been
observed that the customer's 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.
transmissions which initially provided excitement because they made cars
much easier to drive are classified today as a basic quality item.
Customers for a time 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 customer's basic quality needs provides the
foundation for elimination of dissatisfaction and complaints. Exceeding
customer's performance expectations creates a competitive advantage and
innovations differentiate the product and the organization creating an
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 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 better
(higher quality) life forms. In a similar fashion, Genrikh 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.
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 Determination (AFD),
2. Classical TRIZ Problem Solving Tools, and Directed Evolution
(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.
third dimension to quality made possible by TRIZ provides organizations
with powerful tools to fully leverage each of the three quality types. As
important 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.
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 when it is, the consequences that follow.
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 elimination of failure modes.
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.
Quality and Classical TRIZ
is characterized, as the name implies, 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.
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-à-vis a compromise
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 the Problem
Formulator and the System of Operators,
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,
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.
Quality and Directed Evolution™
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 often times 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, 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
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 organizations product
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 Light™ introduced
several years ago by Black & Decker. The Snake Light™ 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
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 the companies 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 represent the most complete and powerful
conceptualization of the quality dynamic and the scientific ability to
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, Messrs. Boris Zlotin and Dana Clarke, and Dr. Stan
Kaplan, for their editorial comments.
Steven Ungvari has
20 years of hands-on experience in teaching and implementing leading edge
productivity and product development methodologies. He has implemented and
consulted in the following disciplines: New Product Development, Supply
Chain Integration, Quality Function Deployment, Organizational
Engineering, Failure Mode & Effects Analysis, The Theory of Inventive
Problem Solving (TRIZ), Lean Manufacturing, The Toyota Production System (TPS)
and many others.
Steve is President
of Strategic Product Innovations Inc., a senior consultant with Beacon
Consulting Services, the former President of The American Supplier
Institute (ASI) and ASI International. Steve is a faculty member of the
American Society for Quality (ASQ). He is recognized in Who’s Who
Worldwide as a knowledgeable and distinguished business leader in his
7591 Brighton Road
Brighton, MI 48116-7722
810-220-8440, Fax 220-3807
Anticipatory Failure Determination™ and AFD™ are Service
Marks of Ideation International Inc.
2. Directed Evolution™ and DE™ are Service Marks
of Ideation International Inc.
3. Problem Formulator™ is a Service Mark of
Ideation International Inc.
4. System of Operators™ is a Service Mark of
Ideation International Inc.