Chapter 1

DEPARTMENT OF
MANUFACTURING AND
MATERIALS ENGINEERING
MME 4116
PRODUCT DESIGN AND
DEVELOPMENT
BY:
DR MOHD RADZI BIN HAJI CHE DAUD

1.1 Introduction
What is design?
Dieter/Schmidt, Engineering Design 5e.
©2013. The McGraw-Hill Companies
3

What is design?
4
• “To fashion after a plan!”
• To design is:
To synthesize new or to arrange existing things in a new way
to satisfy a recognized need of society.
“Design establishes and defines solutions to and pertinent
structures for problems not solved before, or new solutions to
problems which have previously been solved in a different way.”

The Four C’s of Design
5
• Creativity
Requires creation of something that has not existed before or
has not existed in the designer’s mind before.
• Complexity
Requires decisions on many variables and parameters.
• Choice
Requires making choices between many possible solutions
at all levels, from basic concepts to the smallest detail of shape.
• Compromise
Requires balancing multiple and sometimes conflicting
requirements.

1.2 Engineering Design Process
Why is engineering design process
needed?
6

Importance of the Engineering Design
Process
7
• Decisions made in the design process cost very little
in terms of the overall product cost but have a
major effect on the cost of the product.
• You cannot compensate in manufacturing for
defects introduced in the design phase.
• The design process should be conducted so as to
develop quality, cost-competitive products in the
shortest time possible.

Product Cost Commitment during
Phases of the Design Process
8
Adapted from D. Ullman, The Mechanical Design Process, 4th ed., McGraw-Hill, New York,2010.

Types of Designs
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• Original Design: Innovative design
• Adaptive Design
• Redesign: Variant design
• Selection design

1.3 Ways To Think About The
Engineering Design Process
What do we mean by “designing a
system”?
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Simplified Iteration Model
11
Adapted from M. Asimow, Introduction to Design, Prentice-Hall, Englewood Cliffs, NJ, 1962.

Design Method Versus Scientific
Method
12
Adapted from P. H. Hill, The Science of Engineering Design, Holt, Rinehart and Winston, New York 1970.

A Problem-Solving Methodology
13
• Definition of the problem
• Gathering of information
• Generation of alternative solutions
• Evaluation of alternatives and decision making
• Communication of the results

How The Design Depends On How The
Problem Is Defined
14

Design Paradox Between Design
Knowledge and Design Freedom
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1.4 Description of Design Process
What are the steps of Design
Process?
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Design Process Phases
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• Phase I:
Conceptual Design
• Phase III:
Detail Design
• Phase II:
Embodiment Design

Phase I. Conceptual Design
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Phase II. Embodiment Design
19

Phase III. Detail Design
20

Engineering Design Process
21

1.5 Consideration Of A Good
Design
What are the various considerations
of a good design?
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Considerations of Good Design
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1) Achievement of Performance Requirements
2) Life-Cycle Issues
3) Social and Regulatory Issues

Achievement of Performance
Requirements
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• A major characteristic of a design is its function.
• Performance Requirements:
Primary Performance Requirements
Complementary Performance Requirements
Part (Component): A single piece requiring no assembly
Assembly: When two or more parts are joined.
Subassemblies: Smaller assemblies which compose larger
assemblies.

Total Materials Life Cycle
25
Reproduced from “Materials and Man’s Needs,” National Academy of Sciences, Washington, D.C., 1974.

Regulatory and Social Issues
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 The code of ethics of all professional engineering societies
require the engineer to protect public health and safety.
Example of Standards and Codes:
ASME: American Society of Mechanical Engineers
ASTM: American Society for Testing and Materials
OSHA: Occupational Safety and Health Administration
CPSC: Consumer Product Safety Commission
EPA: Environmental Protection Agency
DHS: Department of Homeland Security

1.6 Computer-Aided Engineering
What are the changes that plentiful
computing has produced?
27

Computer-Aided Engineering (CAE)
28
 The advent of plentiful computing has produced a major
change in the way engineering design is practiced.
Advantages of Computer-Aided Engineering:
Automated engineering drawing in two dimensions
Three dimensional modeling
Finite Element Modeling (FEM)
Rapid prototyping
Design optimization
Computer-Aided Design (CAD)
Computer-Aided Manufacturing (CAM)

1.7 Designing To Codes And
Standards
What are the codes and standards?
29

Designing To Codes And Standards
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• A code is a collection of laws and rules that assists a
government agency in meeting its obligation to protect
the general welfare by preventing damage to property
or injury or loss of life to persons.
• A standard is a generally agreed-upon set of
procedures, criteria, dimensions, materials, or parts.
• Efficiency
• Safety
• Interchangeability
• Compatibility
Chief Aspects of Designing To Codes and Standards:
I
n
c
r
e
a
s
e

Two Broad Forms of Codes
31
• Performance Codes are stated in terms of the
specific requirement that is expected to be
achieved.
• Prescriptive(specification) Codes state the
requirements in terms of specific details and
leave no discretion to the designer.
Performance Codes Prescriptive Codes

1.8 Design Review
What is design review?
32

Design Review
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• A design review is a retrospective study of the design up to that point in
time.
• The essence of the technical review of the design is to compare the
findings against the detailed Product Design Specification (PDS).
• The PDS is a detailed document that describes what the design
must be in terms of:
– Performance requirements
– Environment in which it must operate
– Product life
– Quality
– Reliability
– Cost
– Host of other design requirements

Redesign
34
• Two categories of redesigns:
– Fixes
– Updates
• A fix is a design modification that is required due to
less than acceptable performance once the product
has been introduced into the marketplace.
• Updates are usually planned as part of the product’s
life cycle before the product is introduced to the
market.

An Examples of Design Update
35

1.8 Societal Considerations in
Engineering Design
What are the effects of engineering
design on society?
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Societal Considerations in Engineering
Design
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• ABET Code of Ethics:
“Engineers shall hold paramount the safety,
health, and welfare of the public in the
performance of their profession.”
• Some influences on the practice of engineering
design due to increased societal awareness of
technology:
– Greater influence of lawyers on engineering decisions
– More time spent in planning and predicting
– Emphasis on “defensive research and development”
– More effort expended in research, development, and
engineering in environmental control and safety.Dieter/Schmidt, Engineering Design 5e.

Characteristics of an Environmentally
Responsible Design
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• Easy to disassemble
• Able to be recycled
• Contains recycled materials
• Uses identifiable and recyclable plastics
• Reduces use of energy and natural materials
in its manufacture
• Manufactured without producing hazardous
waste
• Avoids use of hazardous materials
• Reduces product chemical emissions

Keys Roles of Government in
Interacting with Technology
39
• As a stimulus to free enterprise through
changes in the tax system
• By influencing interest rates and the supply of
venture capital through changes in fiscal
policy to control the growth of the economy
• As a major customer for high technology,
chiefly in military, space, andS energy systems
• As a funding source (patron) for research and
development
• As a regulator of technologyDieter/Schmidt, Engineering Design 5e.

Chapter 1

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Chapter 1