Product Design
In a systematic approach,
product designers conceptualize and evaluate ideas, turning them into
tangible inventions and products. The product designer's role is to combine
art, science, and technology to create new products that people can use. Their
evolving role has been facilitated by digital tools that now allow
designers to communicate, visualize, analyze and actually produce tangible
ideas in a way that would have taken greater manpower in the past.
The task of developing
outstanding new products is difficult, time-consuming, and costly. People who
have never been involved in a development effort are astounded by the amount of
time and money that goes into a new product. Great products are not simply
designed, but instead they evolve over time through countless hours of
research, analysis, design studies, engineering and prototyping efforts, and
finally, testing, modifying, and re-testing until the design has been
perfected.
Few products are developed
by a single individual working alone. It is unlikely that one individual will
have the necessary skills in marketing, industrial design, mechanical and
electronic engineering, manufacturing processes and materials, tool making,
packaging design, graphic art, and project management, just to name the primary
areas of expertise. Development is normally done by a project team, and the
team leader draws on talent in a variety of disciplines, often from both
outside and inside the company. As a general rule, the cost of a development
effort is a factor of the number of people involved and the time required to
nurture the initial concept into a fully refined product. Rarely can a
production ready product be developed in less than one year, and some projects
can take three to five years to complete.
Product design is
sometimes confused with (and certainly overlaps with) industrial design,
and has recently become a broad term inclusive of service, software, and physical
product design. Industrial design is concerned with bringing artistic form and
usability, usually associated with craft design and ergonomics, together
in order to mass-produce goods. Other aspects of product design include engineering
design, particularly when matters of functionality or utility (e.g.
problem-solving) are at issue, though such boundaries are not always clear.
Quality Function
Deployment
A
critical aspect of building quality into a product is to ensure that the
product design meets customer expectations. This typically is not as easy as it
seems. Customers often speak in everyday language. For example, a product can
be described as “attractive,” “strong,” or “safe.” However, these terms can
have very different meaning to different customers, because what one person
considers to be strong, another may not necessarily accept. To produce a
product that customers want, we need to translate customers’ everyday language
into specific technical requirements. However, this can often be difficult. A
useful tool for translating the voice of the customer into specific technical
requirements is quality function deployment (QFD). Quality function deployment
is also useful in enhancing communication between different functions, such as
marketing, operations, and engineering.
QFD
enables us to view the relationships among the variables involved in the design
of a product, such as technical versus customer requirements. This can help us
analyze the big picture — for example, by running tests to see how changes in
certain technical requirements of the product affect customer requirements. An
example is an automobile manufacturer evaluating how changes in materials
affect customer safety requirements. This type of analysis can be very beneficial
in developing a product design that meets customer needs, yet does not create
unnecessary technical requirements for production.
QFD
begins by identifying important customer requirements, which typically come
from the marketing department. These requirements are numerically scored based
on their importance and scores are translated into specific product characteristics.
Evaluations are made of how the product compares with its main competitors
relative to the identified characteristics. Finally, specific goals are set to
address the identified problems. The resulting matrix looks like a picture of a
house and is often called the house of quality.
Customer
Requirements
Remember
that our goal is to make a product that the customer wants. Therefore, the
first thing we need to do is survey our customers to find out specifically what
they would be looking for in a product. The importance customers attach to each
of these requirements is also determined.
Competitive
Evaluation
On
the far right of our relationship matrix is an evaluation of how our product
compares to those of competitors. For a example there are two competitors, A
and B. The evaluation scale is from one to five —the higher the rating, the
better. The important thing here is to identify which customer requirements we
should pursue and how we fare relative to our competitors. This means that in
designing the product, we could gain a competitive advantage by focusing our
design efforts on a more appealing product.
Product
Characteristics
Specific
product characteristics are on top of the relationship matrix. These are technical
measures.
The Relationship
Matrix
The
strength of the relationship between customer requirements and product
characteristics is shown in the relationship matrix. A negative relationship
means that as you increase the desirability of one variable; you decrease the
desirability of the other. A positive relationship means that an increase in
desirability of one variable is related to an increase in the desirability of
another. This type of information is very important in coordinating the product
design.
The Trade-off
Matrix
The
relationship matrix is beginning to look like a house. The complete house of
quality is build based on above requirements. The next step in the building
process is to put the “roof” on the house. This is done through a trade-off
matrix, which decides how each product characteristic is related to the others
and thus allows us to see what tradeoffs we need to make.
Setting Targets
The
last step in constructing the house of quality is to evaluate competitors’
products relative to the specific product characteristics and to set targets
for our own product. The bottom row of the house is the output of quality
function deployment. These are specific, measurable product characteristics
that have been formulated from general customer requirements.
The
house of quality has been found to be very useful. It is very important see how
it translates everyday terms like “lightweight,” “roominess,” and “nice
looking,” into specific product characteristics that can be used in
manufacturing the product. Note also how the house of quality can help in the
communication between marketing, operations, and design engineering.
Reliability
An
important dimension of product design is that the product functions as
expected. This is called reliability. Reliability is the probability that a
product, service, or part will perform as intended for a specified period of
time under normal conditions. We are all familiar with product reliability in
the form of product warranties. We also know that no product is guaranteed with
100 percent certainty to function properly. However, companies know that a high
reliability is an important part of customer oriented quality and try to build
this into their product design.
Rs
= (R1) (R2) (R3) . . . (Rn)
Where
Rs = reliability of the product or system.
R1...
n = reliability of components 1 through n
Notice
in the previous example that the reliability of the “system” is lower than that
of individual components. The reason is that all the components in a series, as
in the example, must function for the product to work. If only one component
doesn’t work, the entire product doesn’t work. The more components a product
has; the lower its reliability.
For
example, a system with five components in series, each with a reliability of
.90, has a reliability of only (.90)(.90)(.90)(.90)(.90) = (.90)5 = 0.59.
The
failure of certain products can be very critical. One way to increase product
reliability is to build redundancy into the product design in the form of
backup parts. Consider the blackout during the summer of 2003, when most of the
northeastern part of the United States was out of power for days. Critical
facilities, such as hospitals, immediately switched to backup power generators
that are available when the main systems fail. Consider other critical systems,
such as the navigation system of an aircraft, systems that operate nuclear
power plants, the space shuttle, or even the braking system of your car. What
gives these systems such high reliability is the redundancy that is built into
the product design and serves to increase reliability.
Redundancy
is built into the system by placing components in parallel, so that when one
component fails the other component takes over. In this case, the reliability
of the system is computed by adding the reliability of the first component to
the reliability of the second (backup) component, multiplied by the probability
of needing the backup. The equation is as follows:
Notice
that if the reliability of the 1st component is .90, the probability of needing
a second component is equal to the first component failing, which is (1 - .90)
= .10.
Process Management
According
to TQM a quality product comes from a quality process. This means that quality
should be built into the process. Quality at the source is the belief that it
is far better to uncover the source of quality problems and correct it than to
discard defective items after production. If the source of the problem is not
corrected, the problem will continue. For example, if you are baking cookies
you might find that some of the cookies are burned. Simply throwing away the
burned cookies will not correct the problem. You will continue to have burned
cookies and will lose money when you throw them away. It will be far more
effective to see where the problem is and correct it. For example, the temperature
setting may be too high; the pan may be curved, placing some cookies closer to
the heating element; or the oven may not be distributing heat evenly.
Quality
at the source exemplifies the difference between the old and new concepts of
quality. The old concept focused on inspecting goods after they were produced
or after a particular stage of production. If an inspection revealed defects,
the defective products were either discarded or sent back for reworking. All
this cost the company money, and these costs were passed on to the customer.
The new concept of quality focuses on identifying quality problems at the
source and correcting them.
Managing Supplier
Quality
TQM
extends the concept of quality to a company’s suppliers. Traditionally, companies
tended to have numerous suppliers that engaged in competitive price bidding.
When materials arrived, an inspection was performed to check their quality. TQM
views this practice as contributing to poor quality and wasted time and cost.
The philosophy of TQM extends the concept of quality to suppliers and ensures
that they engage in the same quality practices. If suppliers meet preset
quality standards, materials do not have to be inspected upon arrival. Today,
many companies have a representative residing at their supplier’s location,
thereby involving the supplier in every stage from product design to final
production.
Summary
Today’s
concept of quality, called total quality management (TQM), focuses on building
quality into the process as opposed to simply inspecting for poor quality after
production. TQM is customer driven and encompasses the entire company. Before
you go on, you should know the four categories of quality costs. These are
prevention and appraisal costs, which are costs that are incurred to prevent
poor quality, and internal and external failure costs, which are costs that the
company hopes to prevent. You should understand the evolution of TQM and the
notable individuals who have shaped our knowledge of quality. Last, you should
know the seven concepts of the TQM philosophy: customer focus, continuous
improvement, employee empowerment, use of quality tools, product design,
process management, and managing supplier quality.
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