CHAPTER 4
PRODUCT DESIGN
Discussion and Review Questions
1.
Organizations redesign their products because of customer dissatisfaction, sales decline, new
government regulation, liability claims, technological innovation (in products and methods), and
changes in costs and availability of materials and parts.
2.
Idea generation, preliminary market/technical/financial analysis, product planning (objectives,
etc.) and building a business case, concept & prototype development and process design, testing,
and launch.
3.
CAD refers to computer-aided design: computer graphics used for product design. A designer
can easily modify an existing design or create a new one. The designer can readily obtain a
variety of different perspectives as well as other pertinent information that speeds the design
process and frees the designer to concentrate on creative aspects of design. CAD software may
also perform engineering testing on the image of product such as stress analysis.
4.
Standardization is the extent to which there is absence of variety in a part or product. An
Example is standard hex bolts that have a limited number of thread diameters: 1/4, 5/16, 3/8,
7/16, ½ inch etc. The main advantages of standardization (i.e., having limited types, sizes,
colours, etc of a part or product) are:
a. Less variety of parts to deal with.
b. Permits standardized training, purchasing, inspection, and material handling. It may also
permit automation.
c. Enables making to stock, which allows filling orders from inventory and longer production
runs (cheaper unit cost due to economics of scale).
Among the main disadvantages of standardization are:
a. Designs may be locked in, resisting modification of the part.
b. Decreased variety may lessen consumer appeal.
5.
In Modular design, parts are grouped into modules that are easily replaced or interchanged. The
product is composed of a number of modules or components, instead of a collection of
individual parts. Examples include cars and computers. Among the advantages of modular
design are mass customization (quickly assembling modules to achieve customized configurations
for individual customers), simpler purchasing, inventory control, and assembly, and easier
diagnosis of failures. The disadvantage of modular design is not being able to disassemble a
module to replace a faulty part.
6.
Design for manufacturing (DFM) is taking into account the organization’s manufacturing
capabilities when designing a product. An example is trying to avoid designing shapes that are
difficult to fabricate, e.g., inside curves. Design for assembly (DFA) focuses on reducing the
number of parts in a product and on assembly methods and sequence. An example is trying to
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replace screws and nuts & bolts with snap-on. DFM and DFA are important because they affect
cost and speed of production.
7.
concurrent engineering is binging engineering design, manufacturing engineers, and staff from
marketing, manufacturing, and purchasing together early in the design phase.
Some of the competitive advantages of concurrent engineering are:
 Manufacturing personnel are able to identify production capabilities. Very often,
designers have some latitude in design in terms of selecting suitable materials and
processes. Knowledge of production capabilities can help in the selection process. This
will reduce cost, time, and quality problems/conflicts during production.
 Early opportunities for design or procurement of critical machines and components, with
long lead times. This can result in a major shortening of the product design process.
8.
The stage-gate model is a technique in which the product design and development process is
divided into stages separated by gates. The stages are: scoping, building a business case,
development, testing & validation, and launch. The gates are screening mechanisms to
determine if the idea/product is ready to advance to the next stage/phase. See Figure 4-2A.
9.
Like humans, most products have limited life and their own life-cycle. From birth to death,
humans pass through various stages, e.g. birth, growth, maturity, and death. A similar life-cycle is
seen for most products. Product life cycle has to do with the life of a product in the market,
passing through distinct stages, each posing different challenges, opportunities, and problems. A
typical sequence consists of incubation, growth, maturity, saturation and decline. Efforts to
improve design will depend on the stage of the life cycle: In the early stages, more design
changes may occur, whereas during maturity only few minor changes may occur. Many products
have life cycles: A new book, a new car, a new type of corn seed, etc. It is important to know the
length of the life of a product so that a new model or substitute product can be planned in time.
10.
Research and development (R&D) is the design engineering/technical department of a company.
It could generate product ideas (e.g., a lab in a pharmaceutical company), and perform detailed
design, develop the prototype, and perform engineering/reliability tests on it.
Mass customization is producing essentially standard goods or services while incorporating a
certain degree of “customization”. Mass customization can be achieved using delayed
differentiation and modular design. Delayed differentiation or postponement involves producing,
but not quite completing, a product until customer preferences are known. This approach reduces
costs while providing variety. An example of delayed differentiation is McDonald’s grilling meat
patties and storing them until customer orders a sandwich (e.g., cheeseburger, hamburger, etc).
11.
12.
a. Services are generally intangible. Consequently, service design needs to also consider factors
such as peace of mind, convenience, and ambiance. Also, a new service must rely on faith and
trust of customers; thus, the importance of image.
b. Services are often produced and consumed at the same time (e.g. a haircut, a car wash).
Thus, there is less latitude in finding and correcting errors before the customer has a chance
to discover them. Consequently, training, process design, and customer relations are
particularly important. Quality is measured by measuring customer satisfaction
c. Services are more customized, and have higher variety, time variability, and customer
contact.
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69
d. Services have low barriers to entry and exit. This places additional burden on service design
to be innovative but selective.
e. Location is often important to services, with convenience as a major factor. Hence, design of
services and choice of location are often closely linked.
13.
Robust design, proposed by Taguchi, is a design that can function in a broad range of conditions.
For example, all season tires are more robust than summer tires (for dry conditions) or winter
tires (for rain, ice, snow).
14.
Quality function deployment (QFD) is a structured approach for integrating the "voice of the
consumer" into the product design process. After customer requirements are determined, each is
translated into a technical requirement or a characteristic of the product. The purpose of QFD is
to ensure that customer requirements are factored into product design (and component design, and
process design).
15.
Reverse engineering is disassembling a competitor’s product in order to find out what it is
composed of and how the components work, searching for ways to improve own products. For
example, Xerox reverse-engineered Toshiba and other paper copiers in the 1980s, or a textbook
author may look into the competing textbooks to get some ideas. No, it is not unethical if it
doesn’t involve copying/stealing patented components/materials. After all, most designers learn
from other designers and products.
16.
A college/university provides learning to their students, a bank keeps your money safely and
makes it available when needed, a taxi company provides transportation for individuals whereas a
trucking company provides transportation for goods, etc.
Answers to Taking Stock
1.
In designing a product, the major trade-off is marketability of the product and its features/options
vs. the manufacturability and costs. In many cases, the more options and interesting features we
add to the product, the less our ability to manufacture the product at a reasonable cost. Other
tradeoffs are technical; e.g., a safer/stronger car/SUV is heavier, hence will consume more gas
(Note: both safety and fuel efficiency are desirable).
2.
In designing products, we need input from the following groups:





3.
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Upper management, to sponsor it and to ensure that the product in question fits with the
overall mission and objectives of this company.
Marketing, because they have the closest relationship with the customers and the best
understanding of the market demand for various products.
Finance/Accounting/Purchasing departments, because they have knowledge of revenues
and costs involved.
Design/engineering (especially in manufacturers), because they have technical
knowledge and provide a detailed design of the product, test its reliability, and design the
production process.
Manufacturing, because they have the best understanding of the company’s
manufacturing capabilities and quality issues.
Technology has had a very significant impact on product service:
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



4.
Computers can assist in market data collection & analysis
Computer Aided Design (CAD) and simulation
Collaborative design across various locations using private networks and
Internet
Rapid prototyping
Testing equipment
Ethics is the study of standards of behavior that promote human welfare. If a company designs
and produces products that are bad for the environment, then this negatively affects the human
welfare in the long run. However, if the benefits of the product outweigh these harms, then one
could argue that overall the product is good. For example, computers have greatly increased
human welfare. The challenge is to find economical ways to refurbish or recycle products. There
appear to be many opportunities in this area.
Answer to Critical Thinking Exercise
The answers will vary. The following is the outline of the answer for an example.
Product: Comfort bicycle, with high handles and back rest so that the rider can ride perfectly vertical, but
the pedal is below the seat (unlike a recumbent bike where the pedal is in front of the seat).
Legal: Safety issues (Is it stable, even on slippery surface?); Has this design been patented before?
Profitability: Is there a large enough market for it, given a price? Would there be enough profit? How
would it be marketed?
Competitiveness: Are there similar bikes on the market? Will our price be competitive?
Design: Detailed drawing? Material used? Stability? Weight? Durability?
Production: Can it be (easily) manufactured? How? Will it be cost-effective?
Answer to Experiential Learning Exercise
1.
Fuel filter on a Honda Prelude 1997 located in a tight in the engine compartment- hard to replace.
2.
Pepper mill is hard to use (the turning of wrist is difficult), won’t last long (the grinding
mechanism is made of plastic), and won’t work if the quantity of pepper seeds inside is low.
Answers to Internet Exercises
1.
Important design concepts in the design of Boeing 777:



Concurrent Engineering (= working together); has reduced the no. of changes to a
drawing``
Design/build multi-functional teams (including airline service mechanics); up to 238
teams, each averaging 15 members, working on different parts of 777
CAD, using CATIA software; 2,399 workstations connected to a cluster of 8 mainframes;
can check component interconnectivity & accessibility for service; includes knowledgebased software for standard design rules and optimization of design
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71


2.
Testing: computer simulation; 9 prototype planes flying 7000 hours; load and flexibility
tests of wings
Fly-by-wire design = no direct mechanical cables or hydraulics
Wescast’s engineering design technologies used:









3.
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CAD 3D modelling
Virtual Analysis tools
Fluid Dynamics flow simulation
Finite Element structural analysis
Solidification modelling for casting
Rapid prototyping
Flow testing
Durability testing
Engine exhaust simulator
Sand paper, masking tape, scotch tape, overhead projector
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Problems
1.
High
Variability in
Service
d
Moderate
c
Low
b
a
Minimal
High
Medium
Low
Minimal
Degree of Contact with Customer
2.
High
Variability in
Service
Moderate
b, c
Low
a
Minimal
High
Medium
Low
Minimal
Degree of Contact with Customer
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73
3.
4.
Roll Roundness bec. as the roll of paper is being pulled and unwinds on the printing machine, if
it is not perfectly round, it might tear. Tensile Strength is a measure of how strong the paper is
against a pulling force.
Many answers are possible. One is:
Technical
Requirements
Customer Requirements
Tasty
Chocolate
chips
per cookie
Baking
time &
temperature
Shape



Attractive appearance


Soft
Target values
5.
5-7
round
8-10 minutes,
340-360 F
Ink
drying time
Ink
stickiness
Ink
viscosity
Many answers are possible. One is:
Technical
Requirements
Customer Requirements

Writes consistently (no gaps)
Does not smear (ink dries fast)


Writes with little pressure
Target values
74
1-2 seconds
medium sticky
medium thick
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6.
Many answers are possible:
Technical requirements
Customer
requirements
Durable
Expected life
Resistance to
impact
shape
Size
adjustment
mechanism


Strong

Stylish

improved
ventilation
quick and
simple
adjustment
feature for a
one-size-fitsall
Specifications

No. of holes

5 years
Instructor’s Manual, Chapter 4
No dent from
a ball at 100
km/hr
oval
6
See diagram
below
75
7.
Many answers are possible.
Technical requirements
Customer
requirements
Attractive
Form
Gap under
the handle
weight
Diameter of
water hole

Easy to handle
& ergonomic


Light
Less messy
water filling
process


More stability
Specifications

76
Design of the
back
Pointed nose
with lines
(see left
photo below)
1 inch
< 2 pounds
> 1 inch
Triangular
shape (see
right photo
below)
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8.
Many answers are possible:
Customer
requirements
Speed
No. of nails
per sec
Technical requirements
Time until
battery needs
Pressure
recharging
produced
Nail loading
mechanism

Run time

Power

Ease of
loading nails

ergonomics
Specifications

Weight

>1
Instructor’s Manual, Chapter 4
> 4 hours
> 30 PSI
Loading dock
with > 50
collated nails
< 1 kg
77
9.
Many answers are possible:
Customer
requirements
Affordable
price
Technical requirements
Variability
accuracy
among
administrators
No. of steps
required
Mouthpiece

Accurate
readings

Eliminate
technician
variability
Easy to operate



Sanitary
Target values

78
$2,500
±3-5% of
true value
±5%
2
replaceable
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10.
Many answers are possible:
Customer
requirements
Easy to close
Weight
Technical requirements
Force needed
Force
to dislodge
required to
the door stop open the door
Thickness of
insulation

Stays open on
a hill


Easy to open
Doesn’t leak
rain in

Doesn’t allow
road noise in
Target values

Gap between
door and car
body

< 10 kg
> 30
Newtons (~ 3
kg force)
< 20
Newtons
> 2 cm
< 1cm
Mini-case: The Redesign of a Snowboarding Helmet
Paradox Design worked mainly on the development stage of product design, focusing on the shape of the
helmet (called industrial design). This is understandable because this was only a redesign of a successful
snowboarding helmet. Thus, feasibility study in Scoping, Building Business case, and to some extent
testing and validation stages were omitted.
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79
Mini-case: Open Wide and Say “Ultra”
1.
Market Analysis
Harvey’s polled burger lovers across Canada, by telephone and later focus groups. Feedback: go
thicker, juicer, chewier, and tastier.
Concept Development
Chef Bonacini knew how to make burgers with above-mentioned qualities (e.g., the 12 taste
profiles he made), but the challenge was to make them for mass market, kept frozen for weeks
before grilling. Packaging could be part of concept too.
Prototype Development
Bonacini tried 12 taste profiles, and Harvey’s executives tasted each. Exotic flavours were
rejected, leaving three simply seasoned burgers. McCormick Canada was brought in to assist with
spices. Several tests were done with burgers kept frozen for 1, 2, 3, and 4 weeks.
(External) Testing & Validation
Ultra was tested in Harvey’s restaurants in Calgary, Sudbury, and Quebec.
2.
Life Cycles (replacing their old burger) and Robust Design (tests to determine effect of spice on
taste after freezing for various periods).
3.
Many answers are possible.
Technical requirements
Customer
requirements
thicker
Thickness
(given fixed
surface area)
Amount of
water
Cooking time


Juicier

Easier to chew

Tastier
Specifications

80
Seasoning
(salt and
pepper)
1.8 cm
20%
5 minutes at
500 F
1 gr, 1 gr
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