ALL ENGINEERING DESIGN NOTES ,TO COME OUT WITH A QUALITY ENGINEERING DESIGNS

1. PRINCIPLES OF
ENGINEERING DESIGN
CUPE 125
LECTURER: ENG J. BAMHARE
jbamhare@cut.ac.zw

2. Methodology As The Backbone To
Engineering Design
• Methodology is the sequence of steps designed to
achieve a set output in a manner that ensures a high
degree of success when applied
• There is a relevant methodology to all steps of the
design process
• Each prescribed methodology is appropriate and
relevant for a given scenario
• Qualifying and matching each scenario to a given
solution process (methodology) is the responsibility of
the Designer

3. THE DESIGN PROCESS
1. The Need
2. Design Specifications
3. Function and Design Parameter Development
4. Analysis and Synthesis
5. Concept Development
6. Concept Evaluation
7. Application of Design for X methodologies
8. Parameter Design and Experimentation
9. Detailed Design, CAD and Implementation
10. Testing, Evaluation and Design Analysis

4. THE DESIGN PROCESS (CONT.)
• The design process is iterative through out all stages
thus there is need to always compare and evaluate the
design objectives to the progress made at each stage
• This design process applies to product development
primarily
• The research process is also encompassed in the
engineering design process as there is hardly any
design without prior or active research

5. DESIGN AS A FUNCTION OF
QUALITY
• The customer and all aspects concerned with the
customer are a function of Quality
• Quality is the standard of something as measured
against other things of a similar kind; the degree of
excellence of something.
• In business, engineering, and manufacturing, quality
has a pragmatic interpretation as the non-inferiority or
superiority of something; it's also defined as being
suitable for its intended purpose while satisfying
customer expectations

6. DESIGN AS A FUNCTION OF
QUALITY (CONT.)
• The need to satisfy the customer drives the design
process thus making design a function of quality
• The techniques used in marketing and sales to obtain
customer feedback then become the starting point of
improving on or building up a design

7. THE NEED
• This is defined by the Voice of the Customer
• The purpose of this stage is to map the direction along
which the design effort is to take
• This is the make or break stage of the design process,
which affects all consequent efforts

8. THE VOICE OF THE
CUSTOMER
• These are the customer’s expectations for your
products. It focuses on customer needs, expectations,
understandings, and product improvement.
• The list of expectations forms the basis for product
specifications.
• This opinion gathering tool utilizes several techniques
for deployment

9. THE VOICE OF THE CUSTOMER (CONT.)
• Driving Force Behind Specifications
• Customer Dictates Attributes Of Product
• Customer Satisfaction
• Meeting Or Exceeding Customer Expectations
• Customer Expectations Can Be Vague & General In Nature
• Customer Expectations Must Be Taken Literally, Not Translated
Into What The Organization Desires

10. COLLECTING CUSTOMER
INFORMATION
• What Does Customer Really Want ?
• What Are Customer’s Expectations ?
• Are Customer’s Expectations Used To Drive Design
Process ?
• What Can Design Team Do To Achieve Customer
Satisfaction?

11. TECHNIQUES FOR OPINION GATHERING
• Focus Groups,
• Individual Interviews,
• Contextual Enquiry,
• Customer Specifications,
• Observations,
• Warranty Data,
• Field Reports,
• Focus Products e.g. Samsung Smartphones

12. TYPES OF CUSTOMER INFORMATION
• Solicited, Measurable, Routine
• Cus. & Market Surveys, Trade Trials
• Unsolicited, Measurable, Routine
• Customer Complaints, Lawsuits
• Solicited, Subjective, Routine
• Focus Groups
• Solicited, Subjective, Haphazard
• Trade & Cus. Visits, Indep. Consultants
• Unsolicited, Subjective, Haphazard
• Conventions, Vendors, Suppliers

13. CONVERTING NEEDS INTO SPECIFICATIONS
• Customer needs, market needs or customer
requirements along with the product requirements or
specifications are referred to as “design inputs”.
• One of the keys to good product requirements or
specifications is to define measurable and objective
requirements of specifications.
• It is only when a specification is measurable that one can
determine whether that specification has been satisfied
when verification of the product design is performed.
• Quality Function Deployment converts needs into what’s
and how’s

14. QUALITY FUNCTION DEPLOYMENT
• a structured approach to defining customer needs or requirements and
translating them into specific plans to produce products to meet those
needs.
• is a means of translating customer requirements into appropriate
technical requirements for each stage of product or service
development and production.
• This understanding of the customer needs is then summarized in a
product planning matrix or “house of quality”. These matrices are used
to translate higher level “what’s” or needs into lower level “how’s” –
product requirements or technical characteristics to satisfy these needs.

15. BENEFITS OF QFD
• Customer Driven
• Reduces Implementation Time
• Promotes Teamwork
• Provides Documentation

16. CUSTOMER DRIVEN
• Creates Focus On Customer Requirements
• Uses Competitive Information Effectively
• Prioritizes Resources
• Identifies Items That Can Be Acted On

17. REDUCES IMPLEMENTATION TIME
• Decreases Midstream Design Change
• Limits Post Introduction Problems
• Avoids Future Development Redundancies
• Identifies Future Application Opportunities
• Surfaces Missing Assumptions

18. PROMOTES TEAMWORK
• Based On Consensus
• Creates Communication At Interfaces
• Identifies Actions At Interfaces
• Creates Global View-Out Of Details

19. PROVIDES DOCUMENTATION
• Documents Rationale For Design
• Is Easy To Assimilate
• Adds Structure To The Information
• Adapts To Changes (Living Document)
• Provides Framework For Sensitivity Analysis

20. CUSTOMER REQUIREMENTS
Company Measures
Part Characteristics (Design)
Manufacturing Process
Production Requirements
(Day to Day Operations)
QFD Overview
Converted to
Converted to
Converted to
Converted to
QFD:- systematic way for
developing products based on
the needs of the customer.

21. HOUSE OF QUALITY
Technical Descriptors
(Voice of the organization)
Prioritized Technical
Descriptors
Interrelationship
between
Technical Descriptors
Customer
Requirements
(Voiceofthe
Customer)
Prioritized
Customer
Requirements
Relationship between
Requirements and
Descriptors

22. DEVELOPMENT OF QFD
Step 1—List Customer Requirements (WHATs)
Step 2—List Technical Descriptors (HOWs)
Step 3—Develop a Relationship Matrix between WHATs and HOWs
Step 4—Develop an Interrelationship Matrix between
HOWs
Step 5—Competitive Assessments
Step 6—Develop Prioritized Customer Requirements
Step 7—Develop Prioritized Technical Descriptors

23. QFD MATRIX
Absolute Weight and Percent
Prioritized Technical
Descriptors
Degree of Technical Difficulty
Relative Weight and Percent
Target Value
Customer
Requirements
Prioritized
Customer
Requirements
Technical
Descriptors
Primary
Primary
Secondary
Secondary
Technical
Competitive
Assessment
Customer
Competitive
Assessment
Our
A’s
B’s
CustomerImportance
TargetValue
Scale-upFactor
SalesPoint
AbsoluteWeight
Our
A’s
B’s
Relationship between
Customer Requirements
and
Technical Descriptors
WHATs vs. HOWs
Strong
Medium
Weak
+9
+3
+1
Strong Positive
Positive
Negative
Strong Negative
+9
+3
-3
-9
Interrelationship between
Technical Descriptors
(correlation matrix)
HOWs vs. HOWs

24. CUSTOMER REQUIREMENTS (WHAT’S)
CustomerRequirements
(WHATs)
Primary
Secondary
Tertiary

25. TECHNICAL DESCRIPTORS (HOW’S)
TechnicalDescriptors
(HOWs)
Primary
Secondary
Tertiary

26. L - SHAPED DIAGRAM
Customer
Requirements
Technical
Descriptors
Primary
Primary
Secondary
Secondary

27. RELATIONSHIP MATRIX
Customer
Requirements
Technical
Descriptors
Primary
Primary
Secondary Secondary
Relationship between
Customer
Requirements and
Technical Descriptors
WHATs vs. HOWs
Strong
Medium
Weak
+9
+3
+1

28. CORRELATION MATRIX
Customer
Requirements
Technical
Descriptors
Primary
Primary
Secondary
Secondary
Relationship between
Customer Requirements
and
Technical Descriptors
WHATs vs. HOWs
Strong Positive
Positive
Negative
Strong Negative
+9
+3
-3
-9
Interrelationship between Technical
Descriptors (correlation matrix)
HOWs vs. HOWs
Strong
Medium
Weak
+9
+3
+1

29. CUSTOMER COMPETITIVE
ASSESSMENT
Customer
Requirements
Customer
Competitive
Assessment
Ours
A’s
B’s
5
3
1
2
5
1
4
4
Relationship between
Customer Requirements
and
Technical Descriptors
WHATs vs. HOWs
Strong
Medium
Weak
+9
+3
+1

30. 1 3 4 2 1 2 1 4
TECHNICAL COMPETITIVE
ASSESSMENTCustomer
Requirements
Customer
Competitive
Assessment
Our
A’s
B’s
5
3
1
2
5
1
4
4
Relationship between
Customer Requirements
and
Technical Descriptors
WHATs vs. HOWs
Strong
Medium
Weak
+9
+3
+1Technical
Competitive
Assessment
Our
A’s
B’s

31. PRIORITIZED CUSTOMER REQUIREMENTS
• Importance Rating
• Target Value
• Scale-Up Factor
• Sales Point
• Absolute Weight & Percent
• (Importance Rating)
• (Scale-Up Factor)
• (Sales Point)

32. 7
3
9
10
2
4
8
1
Customer
Requirements
Prioritized
Customer
Requirements
Technical
Descriptors
Primary
Primary
Secondary
Secondary
Technical
Competitive
Assessment
Customer
Competitive
Assessment
Our
A’s
B’s
CustomerImportance
TargetValue
Scale-upFactor
SalesPoint
AbsoluteWeight
1 3 4 2 1 2 1 4
5
3
1
2
5
1
4
4
5
3
2
3
5
2
4
4
1.5
1
1.2
1.5
1
1
1.5
1
1.5
1
15
3
Our
A’s
B’s
Relationship between
Customer Requirements
and
Technical Descriptors
WHATs vs. HOWs
Strong
Medium
Weak
+9
+3
+1

33. PRIORITIZED TECHNICAL DESCRIPTORS
• Degree Of Difficulty
• Target Value
• Absolute Weight & Percent
• Relative Weight & Percent
a
j
R
ij
c
i
i
n



1
b
j
R
ij
d
i
i
n



1
R is Relationship Matrix
c is Customer Importance
R is Relationship Matrix
c is Customer Absolute
Weights

34. Absolute Weight and Percent
Prioritized Technical
Descriptors
Degree of Technical Difficulty
Relative Weight and Percent
Target Value
1 8 4 2 9 8 2 5
90
133
2 3 4 3 1 3 1 5
7
3
9
10
2
4
8
1
Customer
Requirements
Prioritized
Customer
Requirements
Technical
Descriptors
Primary
Primary
Secondary
Secondary
Technical
Competitive
Assessment
Customer
Competitive
Assessment
Our
A’s
B’s
CustomerImportance
TargetValue
Scale-upFactor
SalesPoint
AbsoluteWeight
1 3 4 2 1 2 1 4
5
3
1
2
5
1
4
4
5
3
2
3
5
2
4
4
1.5
1
1.2
1.5
1
1
1.5
1
1.5
1
15
3
Our
A’s
B’s
Relationship between
Customer Requirements
and
Technical Descriptors
WHATs vs. HOWs
Strong
Medium
Weak
+9
+3
+1
Strong Positive
Positive
Negative
Strong Negative
+9
+3
-3
-9
Interrelationship between
Technical Descriptors
(correlation matrix)
HOWs vs. HOWs

35. QFD PROCESS
WHATs
HOW
MUCH
HOWs
WHATs
HOW
MUCH
HOWs

36. PHASE I
PRODUCT PLANNING
Design
Requirements
Customer
Requirements

37. PHASE II
PART DEVELOPMENT
Part Quality
Characteristics
Design
Requirements

38. Phase III
Process Planning
Key Process
Operations
PartQuality
Characteristics

39. Phase IV
Production Planning
Production
Requirements
KeyProcess
Operations
Production Launch

40. QFD SUMMARY
• Orderly Way Of Obtaining Information & Presenting It
• Shorter Product Development Cycle
• Considerably Reduced Start-Up Costs
• Fewer Engineering Changes
• Reduced Chance Of Oversights During Design Process
• Environment Of Teamwork
• Consensus Decisions
• Preserves Everything In Writing

41. •Discussion