383
18
Case Studies and
Integration
INTRODUCTION
This chapter provides nine case studies to help the reader integrate a number of
product design issues. The case studies illustrate product development issues and
applications of several techniques covered in the preceding chapters. The case stud-
ies are intended to help the reader in understanding how relatively simple tools can
be applied to gain insights into product design issues and to solve problems related
to the complex products.
The rst case study involves applications of product decomposition, product
attributes, and use of matrix data to determine relative importance of systems in a
motorcycle. The second case study illustrates a benchmarking study of automotive
steering wheels and evaluations of the steering wheels in a driving simulator. The
third case study shows how a Pugh diagram can be used to improve a design concept
by comparing it with existing competitors and the manufacturer’s current product.
The fourth study is about a product development success story where a design team
visited users of pneumatic grinders and developed their new grinder that won a lot of
awards. The fth case study involves a review of a unique product design and assem-
bly features of “Smart”—a two passenger microcar. The sixth case study involved
observations made from watching a 5-hour video on the development of Boeing
777 commercial airliner. The seventh case study is on some unique product features
of Boeing 787 Dreamliner. The eighth case study illustrates a exible process for
assembling a family of complex laptop computer products with a large product vari-
ety. Finally, the ninth case study involves translation of customer needs of an electric
car into its engineering specications.
CASE STUDY 1: MOTORCYCLE SYSTEMS
objectIves
1. To illustrate product decomposition, product attributes, and use of matrix
data to determine relative importance of systems in a motorcycle (a complex
product)
2. To determine the most important systems within a motorcycle from the
view point of customer satisfaction
Project descrIPtIoN
One of the key techniques in managing complex product development is to decom-
pose the product into a number of manageable systems so that the systems can be
384 Designing Complex Products with SE Processes and Techniques
designed in coordination with their interfacing systems. Therefore, this section uses
a motorcycle as an example of the complex product and illustrates its decomposition
into a number of systems.
The systems in the motorcycle are illustrated in Figure 18.1. Each of the systems
can be further decomposed into its subsystems and components of each of the sub-
systems, and a decomposition tree of the motorcycle can be constructed.
motorcycle attrIbutes to systems relatIoNshIPs
Next important step is to identify attributes of the complex product by communi-
cating with its customers. Table 18.1 shows six attributes of the motorcycle in its
left-hand column obtained from interviews with a number of motorcycle owners to
understand their needs.
The table presents a matrix of strength of relationships between the attributes
and the systems in the motorcycle illustrated in Figure 18.1. The strengths of rela-
tionships are indicated by using a 10-point rating scale, where 10 = very strong
relationship, 1 = very weak relationship, and a blank or no scale value illustrates no
relationship. The strengths of relationships were developed by the engineers involved
in benchmarking the motorcycles (see Table 13.1 and Figures 13.1 and 13.2).
The importance ratings of each of the attributes are presented in the last column
of Table 18.1. The importance ratings were obtained by asking the customers to rate
the importance of each attribute by using a 10-point importance rating scale, where
10 = most important and 1 = least important.
Body-frame system
(includes fenders,
trim parts)
Steering system
(handbar, fork)
Wheels and
suspension system
Braking
system
(front)
Braking
system
(rear)
Seat system
Fuel system
(tank, hoses)
Lighting
system
(front)
Lighting
system
(rear-
taillamps
)
Vision system
(windshield,
mirrors)
Hand
controls
Foot
controls
Storage
system
Powertrain system
(engine, transmission)
Radio and
enter
tainment
system
Instrument
panel system
FIGURE 18.1 Illustration of decomposition of a motorcycle into a number of systems.
385Case Studies and Integration
TABLE 18.1
Attributes to Systems Relationship Matrix
Attributes
Body-
frame
System
Steering
System
Wheels and
Suspension
System
Barking
System
Seat
System
Powertrain
System
Fuel
System
Electrical
System
Lighting
System
Vision
System
Instrument
Panel System
Hand
Controls
Foot
Controls
Storage
System
Radio and
Entertainment
System
Importance
Rating
(10= Most
Important;
1 = Least
Important)
Power and
performance
9 5 5 5 5 10
Maneuvering,
handling, and
braking
9 9 9 9 9 9 9 10
Comfort and
convenience
5 9 6 6 5 3 7
Safety 9 9 9 3 9 9 5 9 9 9
Styling and
appearance
9 5 5 3 5 3 3 5 3 3 9 3 6
Costs 9 9 9 5 5 9 5 5 5 3 5 3 3 1 1 8
Absolute
importance
ratings
297 273 227 211 121 279 120 90 139 165 157 298 263 62 47 2,749
Relative
importance
ratings
11 10 8 8 4 10 4 3 5 6 6 11 10 2 2 100
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