THIS WEEK LAB
Form design teams and decide what you’ll design
THIS WEEK HOMEWORK
QFD; Design Specifications
Read:
PDS and QFD
PDS and QFD ES1050 lecture
CDEN2006
Install SolidWorks2011
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ENGINEERING DESIGN PROCESS
1. Specification Development / Planning Phase
Determine need, customer and engineering requirements
Develop a project plan
2. Conceptual Design Phase
Generate and evaluate concepts
Select best solution
This is the extend of
MME2259a design project
3. Detail Design Phase
CAD models
Engineering drawings
Design documentation
Part specification
Prototype and testing
4. Production Phase
Component manufacture and assembly
Plant facilities / capabilities
5. Service Phase
Installation, use , maintenance and safety
6. Product Retirement Phase
Production, service and retirement
phases consideration will have an
impact on the MME2259a design
project, especially in the detailed
design phase.
Length of use, disposal, and recycle
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DESIGN INFLUENCES THE FOLLOWING:
Product Quality
Product Manufacturing Cost
Product Cost
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DESIGN INFLUENCE ON PRODUCT QUALITY
Quality is a composite of factors that are responsibility of the
design engineer.
Decisions made during the design process determine the
product’s quality as perceived by the customers.
Quality cannot be built into a product unless it is designed into it
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DESIGN INFLUENCE ON MANUFACTURING AND PRODUCT COST
100
% of product cost
committed
% of product
manufacturing cost
committed
80
60
40
20
0
Specification
Development
Conceptual
Design
Time
Detailed Design
Note that ¾ of the product cost associated with design is committed by the end of the
conceptual design phase
Early design decisions have the greatest effect on the final product cost.
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DESIGN PROCESS PARADOX
Freedom
Knowledge of Design
100%
Design Freedom
0%
Time into Design Process
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SEQUENTIAL VS. CONCURRENT
PRODUCT DEVELOPMENT
Marketing
Research and
Development
Engineering
Manufacturing
Sequential Product Development should be avoided
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SEQUENTIAL VS. CONCURRENT
PRODUCT DEVELOPMENT
Marketing
Research and
Development
Engineering
Voice of
customer
Satisfaction of
customer needs
Service
Manufacturing
Concurrent Product Development is preferred
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WE ARE NOW READY TO DESIGN A PRODUCT
BUT HOW DO WE KNOW THAT CUSTOMERS WILL BUY IT?
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Time was when a man could order a pair of shoes directly from the cobbler. By
measuring the foot himself and personally handling all aspects of manufacturing,
the cobbler could assure the customer would be satisfied
http://www.qfdi.org
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TODAY MANUFACTURING HAPPENS VERY FAR FROM CUSTOMERS,
IT’S EASY TO LOST TOUCH ...
As marketing
requested it
As sales ordered it
As production
manufactured it
As plant installed it
As engineering designed it
What the customer really wanted !!
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IMPORTANCE OF CUSTOMER RESEARCH
Customer research is essential to developing any new
product or service. Without a complete understanding of
your customers’ wants and needs, you may be developing a
product that is out-of-sync with your market and ultimately
doomed to failure.
http://www.ams-inc.com/
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DIFFERENT WAYS TO FIND WHAT
CUSTOMERS NEED AND WANT
Use existing feedback
Surveys
Customer interviews
Competitive analysis
Just ask them
•
Actual ways companies use to find customers’
needs and wants are tightly guarded trade secrets!
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CUSTOMER REQUIREMENTS
WHAT?
• Must be discriminatory
• Must be measurable
• Must be orthogonal: no overlapping of requirements,
each requirement should identify a unique feature
• Must be universal: applicable to all alternatives under
consideration
• Must be external to problem: must not impose design
choices
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CUSTOMER REQUIREMENTS
Must be discriminatory
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CUSTOMER REQUIREMENTS
Must be measurable
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CUSTOMER REQUIREMENTS
Must be orthogonal: no overlapping of requirements,
each requirement should identify a unique feature
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CUSTOMER REQUIREMENTS
Must be universal: applicable to all alternatives
under consideration
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CUSTOMER REQUIREMENTS
Must be external to problem;
must not impose design choices
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WE SATISFY CUSTOMER REQUIREMENTS BY DESIGNING
A PRODUCT THAT IS CHARACTERIZED BY CERTAIN
SPECIFICATIONS
CUSTOMER
PRODUCT
REQUIREMENTS
DESIGN SPECIFICATION
WHAT?
HOW?
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PRODUCT DESIGN SPECIFICATIONS
HOW
Other names for engineering design specifications include:
• Engineering design specifications
• Engineering requirements
• Design requirements
• Functional requirements
• Objectives and constraints
• Technical requirements
• Technical specifications
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PRODUCT DESIGN SPECIFICATION (PDS) LIST
Is a detailed summary of the design requirements to be met in
order to produce a successful product or process.
BASIC APPROACH TO CREATE PDS
Write a separate specification for each element of the PDS list.
If possible, the specification should be expressed in quantitative
terms, and when appropriate it should give limits within which
acceptable performance lies.
Performance attributes may be divided into:
(i)
(ii)
attributes that must be satisfied
attributes that you want to satisfy
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PRODUCT DESIGN SPECIFICATIONS (PDS) LIST
1.
Performance - List the functions to be performed by the product, and the desired level of
performance (eg. engineering requirements, targets, specifications).
2.
Operating Environment - Specify the operating environment for the product (eg. range of
temperature, pressure range, abuse by operator, etc).
3.
Standards - List relevant standards that must be adhered to (eg. ANSI, ASTM, CSA, ISO)
4.
Materials - Poorly chosen materials can lead to product failure or unnecessary costs (eg.
material performance characteristics, key material properties)
5.
Customer - List any information on customer likes, dislikes, preferences, and prejudices
(customer driven design)
6.
Ergonomics - Identify any man-machine interfaces (eg. need for handles, buttons, displays…).
7.
Aesthetics, Appearance and Finish - Consider color, shape, texture, and form at the onset of
the design (this is what the customer sees first).
8.
Competition Benchmarking - Perform a thorough analysis of existing and future competitors
(determine how the customer perceives the competition’s ability to meet each design
requirement).
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PRODUCT DESIGN SPECIFICATIONS (PDS) LIST
9.
Quality and Reliability - High risk areas of the product should be identified, and the risks
minimized using formal trade-off techniques in the design process (product must meet or
exceed customer’s expectations).
10.
Testing and Inspection - Specify the tests required to demonstrate that the product
meets the desired specifications, and any quality requirements.
11.
Maintenance and Logistics - Specify ease of access to the components likely to require
maintenance (speed and ease of repair can influence customer’s acceptance of the
product).
12.
Service Life - Establish the expected service life and operation duty cycle for the product
(How long is it expected to last while in operation).
13.
Market Constraints - List any feedback from the marketplace.
14.
Target Product Cost - Establish selling cost at the onset of the design process (Retail
price is often 3X manufacturing cost for mass produced items).
15.
Quantity - Estimate the number of products to be produced (cost/unit to fabricate is
influenced by production method).
16.
Product Life Span - Predict how long the product is to remain on the market (influences
investment decisions, potential sales).
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PRODUCT DESIGN SPECIFICATIONS (PDS) LIST
17.
Shelf Life in Storage - Consideration must be made for protecting parts from the
natural elements while not in use (some products must be stored on hazardous sites for
prolonged periods of time).
18.
Size - This is an important constraint for shipping, storage and marketing.
19.
Weight - An important factor in handling a product on the manufacturing floor,
transportation and installation (weight is related to size and cost).
20.
Shipping - Determine how the product will be delivered to the customer (size of box
cars, weight on transport trucks).
21.
Packaging - Specify the type of packaging required for shipping and storage (protection
during transportation, display).
22.
In-House Processes - Identify any specified treatment of parts (eg. heat treatment,
water resistant coating).
23.
Manufacturing Facilities - Determine whether the product is to be produced in an
existing facility or a new plant must be built (effects design choices such as materials
and shape, directly effects cost).
24.
Patents - Consult all areas of useful information prior to launching the design (prevent
costly lawsuits).
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PRODUCT DESIGN SPECIFICATIONS (PDS) LIST
25. Design Schedule - List definite milestones that the design team is required to meet
(schedule adequate time to due design activity, testing).
26. Company Constraints - Any constraints imposed by company must be spelled out (limits
on new plant investments, preferred vendors/suppliers).
27. Social and Political Factors - List any constraints arising from government regulation (eg.
pollution laws, seatbelt legislation, …).
28. Safety - Critical parts whose failure will cause injury must be identified and documented
(Warning labels should be devised and operating manuals should clearly spell out what is
abusive use of the product).
[Ullman 1992]
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YOU WILL HAVE TO DEVELOP DESIGN SPECIFICATIONS
CONSIDERING THESE 28 FACTORS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
Performance
Operating Environment
Standards
Materials
Customer
Ergonomics
Aesthetics, Appearance and Finish
Competition Benchmarking
Quality and Reliability
Testing and Inspection
Maintenance and Logistics
Service Life
Market Constraints
Target Product Cost
Quantity
Product Life Span
Shelf Life in Storage
Size
Weight
Shipping
Packaging
In-House Processes
Manufacturing Facilities
Patents
Design Schedule
Company Constraints
Social and Political Factors
Safety
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PRODUCT DESIGN SPECIFICATION: A WATER MIXER TAP
Selected specifications:
Maximum pressure
15 bar
Maximum temperature 60OC (standard)
time)
Flow
20L/min
Service life
8 years
100OC (short
These specifications are input for a designer’s analysis of the
required functionality and constraints.
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PRODUCT DESIGN SPECIFICATION: A WATER MIXER TAP
The specification is an input for a designer’s analysis of the required functionality and
constraints.
For example:
The flow of water is either stopped or metered such that the mixed temperature can be adjusted
to any desired value regardless of the water flow rate. Furthermore, the water flow rate must
remain unchanged as temperature changes.
Functions:
Meter
Stop
Adjust
Mix
Inputs:
Pressure
Flow rate
Temperature of hot and cold water
Outputs:
Pressure
Flow rate
Temperature of mixed water
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PRODUCT DESIGN SPECIFICATION: AN ELECTRIC TOOTHBRUSH
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PRODUCT DESIGN SPECIFICATION: A SEAT SUSPENSION
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WE NOW KNOW WHAT ARE CUSTOMERS NEEDS AND WE KNOW
HOW TO DEVELOP PRODUCT SPECIFICATIONS TO MEET THOSE
NEEDS.
HOWEVER, DESIGN PROCESS IS FULL OF TRADE-OFFS AND NOT
ALL SPECIFICATIONS CAN BE FULLY SATISFIED. WE NEED A WAY
TO PRIORITIZE THOSE SPECIFICATIONS.
WE ALSO NEED A QUANTITATIVE WAY TO COMPARE OUR (YET TO
BE DESIGNED) PRODUCT TO EXISTING COMPETITIVE
PRODUCTS.
HOW DO WE CONNECT CUSTOMERS’ NEEDS TO PRIORITIZED
DESIGN SPECIFICATIONS?
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WE SATISFY CUSTOMER REQUIREMENTS BY DESIGNING
A PRODUCT IS CHARACTERIZED BY CERTAIN SPECIFICATIONS
CUSTOMER
PRODUCT
REQUIREMENTS
DESIGN SPECIFICATION
WHAT?
HOW?
QFD LINKS CUSTOMER REQUIREMENTS WITH
PRODUCT DESIGN SPECIFICATIONS
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QUALITY FUNCTION DEPLOYMENT (QFD)
Deployment:
The distribution of forces in preparation for battle or work
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QUALITY FUNCTION DEPLOYMENT (QFD)
QFD was developed to bring this personal interface to modern manufacturing
and business. In today's industrial society, where the growing distance between
producers and users is a concern, QFD links the needs of the customer (end
user) with design, development, engineering, manufacturing, and service
functions.
Quality Function Deployment is a technique developed in Japan during the mid1970's for better understanding the design problem, in particular of customer
needs and to relate them to product design specifications.
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AN INFLATABLE KAYAK
In class exercise
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AN INFLATABLE KAYAK
STEPS IN QFD EXERCISE
1.
Identify the customers
2.
Determine the customers' requirements: What do the customers want?
3.
Determine relative importance of the requirements
4.
Generate engineering specifications: How will the customers' requirements be met?
5.
Relate customers requirements to engineering specifications
6.
Identify relationships between engineering requirements
7.
Identify and evaluate the competition: How satisfied is the customer now?
8.
Set engineering targets: How much is good enough?
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1. Identify customers:
Who are they?
CORRELATION
MATRIX
ENGINEERING
WHO?
RELATIONSHIP
MATRIX
COMPETITION
IMPORTANCE
CUSTOMER REQUIREMENTS
REQUIREMENTS
TARGETS
QFD Chart also called HOUSE OF QUALITY
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2. Determine customers’ requirements:
What do customers need and want?
CORRELATION
MATRIX
ENGINEERING
WHO?
RELATIONSHIP
MATRIX
COMPETITION
IMPORTANCE
CUSTOMER REQUIREMENTS
REQUIREMENTS
TARGETS
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3. Determine the relative importance of
customers’ requirements.
CORRELATION
MATRIX
ENGINEERING
WHO?
RELATIONSHIP
MATRIX
COMPETITION
IMPORTANCE
CUSTOMER REQUIREMENTS
REQUIREMENTS
TARGETS
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4. Generate engineering requirements (PDS):
How will the customers’ requirements be met?
CORRELATION
MATRIX
ENGINEERING
WHO?
RELATIONSHIP
MATRIX
COMPETITION
IMPORTANCE
CUSTOMER REQUIREMENTS
REQUIREMENTS
TARGETS
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5. Relate customers’ requirements to
engineering requirements
CORRELATION
MATRIX
ENGINEERING
WHO?
RELATIONSHIP
MATRIX
COMPETITION
IMPORTANCE
CUSTOMER REQUIREMENTS
REQUIREMENTS
TARGETS
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6. Identify relationships between
engineering requirements
CORRELATION
MATRIX
ENGINEERING
WHO?
RELATIONSHIP
MATRIX
COMPETITION
IMPORTANCE
CUSTOMER REQUIREMENTS
REQUIREMENTS
TARGETS
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7. Identify and evaluate competition.
How satisfied is the customer now?
CORRELATION
MATRIX
ENGINEERING
WHO?
RELATIONSHIP
MATRIX
COMPETITION
IMPORTANCE
CUSTOMER REQUIREMENTS
REQUIREMENTS
TARGETS
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8. Set engineering targets
How much is good enough?
CORRELATION
MATRIX
ENGINEERING
WHO?
RELATIONSHIP
MATRIX
COMPETITION
IMPORTANCE
CUSTOMER REQUIREMENTS
REQUIREMENTS
TARGETS
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HAVE WE MET OUR TARGETS AT THE
END OF THE DESIGN PROCESS?
End of design
Beginning of design
process: PDS
Process: Prototype
?
We’ll do this at the end of the design project
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AN INFLATABLE KAYAK
Competitor A
Competitor B
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AN INFLATABLE KAYAK
Mass
76
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DESIGN INFLUENCE ON PRODUCT COST
% of product
cost
committed
100
80
60
40
20
0
Specification
Development
Conceptual
Design
Detailed Product
Design
Time
Having completed the design specification phase we
have already committed 40% of product cost!
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FOUR PHASE QFD APPROACH
1. Product Planning- Translating what the customer wants (in their language, e.g., portable,
convenient phone service) into a list of prioritized product/service design requirements (in your
language, e.g., cell phones) that describes how the product works. It also compares your
performance with your competition's, and sets targets for improvement to differentiate your
product/service from your competitor's.
2. Part Planning - Translating product specifications (design criteria from step 1) into part
characteristics (e.g., light weight, belt-clip, battery-driven, not-hardwired but radio-frequency
based).
3. Process Planning - Translating part characteristics (from step 2) into optimal process
characteristics that maximize your ability to deliver Six Sigma quality
4. Production Planning - Translating process characteristics (from step 3) into manufacturing
or service delivery methods that will optimize your ability to deliver Six Sigma quality in the most
efficient manner (e.g., cellular antennas installed with overlapping coverage to eliminate
dropped calls).
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FOUR PHASE QFD APPROACH
Product
Planning
Component
Design
Process
Planning
Production
Planning
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TWO PHASE QFD APPROACH
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LOG SPLITTER
Customer requirements
Any log size
Works fast
Tow-able
Lightweight
Inexpensive
Last forever
…
Partial PDS
Size of log
Width
Diameter
Time to split
Type of wood (pine, oak, …)
Weight
Portability
Terrain?
Max towing speed?
…
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