In A Summary of
Product Design and Development
By Steven Eppinger & Karl Ulrich
Aim of this Summary:
To help the readers of this book with a quick summary of the main topics covered in the book
Icons used in this summary




To be included in the course reports
To-do
Note
Definition
CHAPTER FIVE
Identifying Customer Needs

-

1.
2.
3.
4.
5.
Goals:
Ensure that the product is focused on customer needs
Identify latent or hidden needs as well as explicit needs
Provide a fact base for justifying the product specifications
Create an archival record of the needs activity of the development process
Ensure that no critical customer need is missed or forgotten
Develop a common understanding of customer needs among team members of the development team
Five-step Method
Gather raw data from customers
Interpret the raw data in terms of customer needs
Organize the needs into a hierarchy of primary, secondary, and (if necessary) tertiary needs.
Establish the relative importance of the needs
Reflect on the results and the process


Step 1: gather raw data from customers
Mission Statement (charter or design brief) = the way a firm typically specifies a particular market opportunity and lays out the broad
constraints and objections for the project
Product planning process  Mission statement
1.
2.
3.
-
Interviews (single customer, in the use environment, last one to two hours, primary data collection method)
Focus groups (discussion with a group of 8 to 12 customers, videotaped)
Observing the product in use
Written surveys simply do not provide enough information about the use environment of the product, and they are generally ineffective
in revealing unanticipated needs.
A 2-hour focus group = two 1-hour interviews
-
Choosing customers
-
10<Number of interviewees<50
Lead users = customers who experience needs months or years ahead of the majority of the market and stand to benefit substantially
from paroduct innovations
Extreme users = those who use the product in unusual ways or who have special needs
-
The Art of Eliciting Customer Needs Data

Some helpful questions:
-
When and why do you use this type of product?
Walk us through a typical session using the product.
What do you like about the existing products?
What do you dislike about the existing products?
What issues do you consider when purchasing the product?
What improvements would you make to the product?

Some general hints for effective interaction with the customers
-
Go with the flow.
Use visual stimuli and props
-

Suppress preconceived hypotheses about the product technology
Have the customer demonstrate the product and/or typical tasks related to the product.
Be alert for surprises and the expression of latent needs
Watch for non-verbal information
Documenting interactions with customers
1. Audio recording
2. Notes (to be transcribed immediately after the interview)
3. Video recording (raw material for presentations to upper management, multiple watching to elicite latent needs, useful for capturing
and users’ environment)
4. Still photography


Data-gathering process  a set of raw data (customer statements)
Customer
Address
Telephone
Willing to do follow-up?
Question/Prompt
Typical uses
Likes - current tool
Dislikes - current tool
Suggested improvements
………………………..
Bill Esposito
100 Memorial Drive
617-864-1274
Yes
Interviwer(s):
Date:
Currently uses:
Type of user:
Customer Statement
I need to drive screws fast, faster than
I sometimes do duct work; use sheet
A lot of electrical; switch covers, outlets,
……………………..
I like the pistol grip; it feels the best.
I like the magnetized tip.
……………………
I don’t like it when the tip slips off the
I would like to be able to lock it so I can
Cant drive screws into hard wood
Sometimes I strip tough screws.
……………………..
An attachment to allow me to reach
A point so I can scrape paint off of crews.
Would be nice if it could punch a pilot
………………………
………………………
Jonathan and Lisa
19-Dec-10
Craftsman Model A3
Building maintenance
Interpreted Need
The SD drives screws faster than by
The SD drives sheet metal screws into
The SD can be used for screws on
…………………….
The SD is comfortable to grip.
The SD tip retains the screw before it is
……………….
The SD tip remains aligned with the
The user can apply torque manually to
The SD can drive screws into hard wood.
The SD does not strip screw heads.
……………………
The SD can access screws at the end of
The SD allows the user to work with
The SD can be used to creat a pilot hole.
…………………..
…………………..
Step 2: Interpret Raw Data in Terms of Customer Needs
(Is listed in the second column)
-
Express the need in terms of what the product has to do, not in terms of how it might do it.
Express the need as specifically as the raw data
Use positive, not negative, phrasing
Express the need as an attribute of the product
Avoid the words must and should
Step 3: Organize the Needs into a Hierarchy
1.
2.
3.
4.
5.
6.
Primary needs (the most general needs)
Secondary needs (needs in more detail)(done on a wall or table)
Print or write each need statement on a separate card or self-stick note.
Eliminate redundant statements
Group the cards according to the similarity of the needs they express
For each group, choose a label
Consider creating subgroups consisting of two to five groups
Review and edit the organized need statement
Step 4: Establish the Relative Importance of the Needs
Through team consensus or surveys
Step 5: Reflect on the Results and the Process
-
Have we interacted with all of the important type of customers in our target market?
Are we able to see beyond needs related only to existing products in order to capture the latent needs of our target customers
Are there areas of inquiry we should pursue in follow-up interviews or surveys?
Which of the customers we spoke to would be good participants in our ongoing development efforts?
What do we know now that we didn’t know when we started? Are we surprised by any of the needs?
Did we involve everyone within our own organization who needs to deeply understand customer needs?
How might we improve the process in future efforts?
CHAPTER SIX
Product Specifications (Part one)

-
= the precise description of what the product as to do
Specification = a metric + a value
Target specifications = the hopes and aspirations of the team (Discussed here in part one)
Final specifications = specifications after assessing the actual technological constraints and the expected production costs (discussed
later in part two)
Establishing Target Specifications
Step 1: Prepare the List of Metrics


-
A good way to generate the list of metrics is to contemplate each need in turn and to consider what precise, measurable
characteristic of the product will reflect the degree to which the product satisfies that need.
-
Needs – Metrics matrix represents the relationship between needs and metrics.
1
Reduces vibration to the hands
2
Allows easy traversal of slow, difficult terrain
3
Enables high-speed descents on bumpy trails
4
Allows sensitivity adjustment
5
Preserves the steering characteristics of the bike
6
Remains rigid during hard cornering
7
Is lightweight
8
Provides stiff mounting points for the brakes
9
Fits a wide variety of bikes, wheels, and tires
10
Is easy to install
11
Works with fenders
12
Instills pride
13
Is affordable for an amateur enthusiast
14
Is not contaminated by water
15
Is not contaminated by grunge
16
Can be easily accessed for maintenance
17
Allows easy replacement of worn parts
18
Can be maintained with readily available tools
19
Lasts a long time
20
Is safe in crash
Metric
l
l
l
13
14
Wheel sizes
Maximum tire width
18
17
16
22
25
26
Bending strength (frontal loading)
24
Japan Industrial Standards test
Monster cycles to failure
UV test duration to degrade rubber parts 23
Special tools required for maintenance
Time to disassemble/assemble for maintenance
21
Cycles in mud chamber without contamination
20
Time in spray chamber without water entry19
Unit manufacturing cost
Instills pride
Fender compatibility
15
12
Steer tube length
Time to assemble to frame
11
10
9
Headset sizes
Lateral stiffness at the tip
Total mass
8
7
Rake offset
Lateral stiffness at brake pivots
6
Maximum travel (26-in. wheel)
5
4
Minimum descent time to test track
Damping coefficient adjustment range
3
2
Maximum value from the Monster
Spring preload
Attenuation from dropout to handlebar at110 Hz
Need
l l
l
l l
l
l l
l
l
l
l l l l
l
l
l
l
l
l
l
l l
l
l l
l l

Guidelines for constructing the list of metrics:
-
Metrics should be complete (one or multiple metrics could cover a single need)
Metrics should be dependent, not independent variables (dependent variable are useful for making trade offs)
Metrics should be practical (easy to measure or analyze)
Some needs cannot easily be translated into quantifiable metrics (like pride  subjective needs to be evaluated by a panel of customers)
The metrics should include the popular criteria for comparison in the marketplace (Magazines, Reports) (high performance in the media
may be a need by itself)

Importance rating of a metric
= importance rating of the corresponding need + discussion (if the metric covers more than one customer need)
Metric No. Need Nos.
Metric
Imp.
Units
1
1, 3
Attenuation from dropout to handlebar at 10 Hz
3
dB>
2
3
4
5
6
7
8
9
10
2, 6
1, 3
1, 3
4
5
5
6
7
8
Spring preload
Maximum value from the Monster
Minimum descent time to test track
Damping coefficient adjustment range
Maximum travel (26-in. wheel)
Rake offset
Lateral stiffness at brake pivots
Total mass
Lateral stiffness at the tip
3
5
5
3
3
3
3
4
2
N
g
s
N-s/m
mm
mm
kN/m
kg
kN/m
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
9
9
9
9
10
11
12
13
14
15
16, 17
17, 18
19
19
20
20
Headset sizes
Steer tube length
Wheel sizes
Maximum tire width
Time to assemble to frame
Fender compatibility
Instills pride
Unit manufacturing cost
Time in spray chamber without water entry
Cycles in mud chamber without contamination
Time to disassemble/assemble for maintenance
Special tools required for maintenance
UV test duration to degrade rubber parts
Monster cycles to failure
Japan Industrial Standards test
Bending strength (frontal loading)
5
5
5
5
1
1
5
5
5
5
3
3
5
5
5
5
in.
mm
List
in.
s
List
Subj.
US$
s
k-cycles
s
List
hr
Cycles
Binary
kN
Spet 2: Collect Competitive Benchmarking Information
Rox
Rox
ST
Maniray Tahx
Tahx
Tritrack
2
Quadra Ti 21
Tonka
Pro
Gunhill
Head
Shox
15
9
13
500
710
480
680
3.2
3.7
3.3
3.7
3.4
13
0
11.3
0
12.6
0
11.2
200
13.2
0
11
0
mm
mm
28
41.5
48
39
43
38
46
38
33
43.2
38
39
kN/m
kg
kN/m
59
1.409
295
110
1.385
550
1.000
1.125
1.250
85
1.409
425
65
1.222
325
130
1.1
650
1.000
1.125
1.000
1.125
NA
140
165
190
215
150
170
190
210
150
190
210
220
NA
26 in.
1.5
35
None
3
80
26 in.
1.5
85
All
5
100
2300
>3600
Metric
No.
Need
Nos.
Metric
Imp.
1
1, 3
Attenuation from dropout
to handlebar at 10 Hz
3
dB
8
15
10
2
2, 6
3
N
550
760
3
1, 3
5
g
3.6
4
5
1, 3
4
5
3
s
N-s/m
6
7
5
5
3
3
8
9
10
6
7
8
3
4
2
Spring preload
Maximum value from the
Monster
Minimum descent time to
test track
Damping coefficient
Maximum travel (26-in.
wheel)
Rake offset
Lateral stiffness at brake
pivots
Total mass
Lateral stiffness at the tip
Units
12
9
Steer tube length
5
mm
1.000
1.125
150
180
210
230
255
13
14
15
16
17
18
9
9
10
11
12
13
5
5
1
1
5
5
List
in.
s
List
Subj.
US$
26 in.
1.5
35
Zefal
1
65
26 in.
1.75
35
None
4
105
26 in.
1.5
45
None
3
85
19
14
Wheel sizes
Maximum tire width
Time to assemble to
Fender compatibility
Instills pride
Unit manufacturing cost
Time in spray chamber
without water entry
85
1.364
425
1.000
1.125
1.250
150
170
190
210
230
26 in.
700C
1.75
45
None
5
115
5
s
1300
2900
>3600
>3600
11
9
Headset sizes
5
in.

Step 3: Set Ideal and Marginally Acceptable Target Values

This step is time consuming involving purchasing, testing, disassembling and estimating production costs.
Two types of target value are useful:
-
Ideal values (best result)
Marginally acceptable value (barely acceptable)

Five ways to express values of metrics:
-
At least X
At most X
Between X and Y
Exactly X (to be avoided because they are constraining, often can be expressed as “between X and Y”)
A set of discrete values
Metric Need
No.
Nos.
1
2
3
4
5
6
7
8
9
10
1, 3
2, 6
1, 3
1, 3
4
5
5
6
7
8
11
9
Metric
Imp.
Units
Marginal
Value
Attenuation from dropout to handlebar at 10 Hz
Spring preload
Maximum value from the Monster
Minimum descent time to test track
Damping coefficient adjustment range
Maximum travel (26-in. wheel)
Rake offset
Lateral stiffness at brake pivots
Total mass
Lateral stiffness at the tip
3
3
5
5
3
3
3
3
4
2
dB>
N
g
s
N-s/m
mm
mm
kN/m
kg
kN/m
>10
480-800
<3.5
<13.0
0
33-50
37-45
>65
<1.4
>325
Headset sizes
5
in.
1.000
1.125
Ideal
Value
12
9
Steer tube length
5
mm
150
170
190
210
13
14
15
16
17
18
9
9
10
11
12
13
Wheel sizes
Maximum tire width
Time to assemble to frame
Fender compatibility
Instills pride
Unit manufacturing cost
5
5
1
1
5
5
List
in.
s
List
Subj.
US$
26 in.
>1.5
<60
None
>3
<85
>15
650-700
<3.2
<11.0
>200
45
38
>130
<1.1
>650
1.000
1.125
1.250
150
170
190
210
230
26 in.
700C
>1.75
<35
All
>5
<65
19
20
21
22
23
24
25
26
14
15
16, 17
17, 18
19
19
20
20
Time in spray chamber without water entry
Cycles in mud chamber without contamination
Time to disassemble/assemble for maintenance
Special tools required for maintenance
UV test duration to degrade rubber parts
Monster cycles to failure
Japan Industrial Standards test
Bending strength (frontal loading)
5
5
3
3
5
5
5
5
s
k-cycles
s
List
hr
Cycles
Binary
kN
>2300
>15
<300
Hex
>250
>300k
Pass
>7.0
>3600
>35
<160
Hex
>450
>500k
Pass
>10.0

Note that these specifications are preliminary because until a product concept is chosen and some of the design details are worked out,
many of the exact trade-offs are uncertain.
Step 4: Reflect on the Results and the Process
Questions to be considered:
-
Are members of the team “gaming” (trying to exaggerate in order to make sure that the goals are met)?
Multiple products / multiple product options or one “average” product?
Are any specifications missing?
Do the specifications reflect the characteristics that will dictate commercial success?
CHAPTER SEVEN
Concept Generation




Product Concept = an appropriate description of the technology, working principles, and form of the product. It is a concise description
of how the product will satisfy the customer needs.
A concept = a sketch / rough 3D model + brief textual description
Customer needs + target specifications Concept Generation  a set of product concepts
Common Dysfunctions during concept generation:
Consideration of only one or two alternatives, often proposed by assertive members
Failure to consider usefulness concepts in competing products
Involvement of only one or two people in the process, resulting in lack of confidence and commitment by others
Ineffective integration of promising partial solutions
Failure to consider entire categories of solutions
1- Clarify the problem
 Understanding
 Problem
decomposition
 Focus on critical
subproblems
Subproblems
2




Search externally
Lead users
Experts
Patents
Literature
Benchmarking
3- Search internally
 Individual
 Group
Existing Concepts
New Concepts
4- Explore systematically
 Classification tree
 Combination table
Integrated Solutions

5- Reflect on the
solutions and the
process
 Constructive
feedback
Step 1: Clarify the Problem


Understanding  breaking the problem down
To begin you have:
-
Assumptions (will use nails, compatible with existing nail magazines, will nail through roofing shingles into wood, handheld)
Needs (nails in rapid succession, is lightweight, no nailing delay after tripping)
Target Specification (Nail lengths from 25 to 38mm, Maximum nailing energy of 40 J/nail, Nailing forces of up to 2000 newtons, Peak
nailing rate of 1 nail/min, Mass less then 4kg, Maximum trigger delay of 0.25s)
 Problem Decomposition (there are various ways)
1. Functional decomposition (for technical products)
Energy (?)
Material (nails)
Signal (tool “trip”)
Energy (?)
Handheld
Nailer
Material (driven nails)
Signal (?)
Conversion of
energy
Movement of material
Flows of control and feedback
signals
Energy
Nails
“Trip” of Tool
Store or accept
external energy
………………………
Convert energy
to translational
energy
Store nails
………………….
Isolate nail
Sense trip
………………
Trigger tool
Convert energy
to translational
energy
- Create between 3 to 10 working principles
- No specific technological working principle should be implied
2. Decomposition by sequence of user interactions (for products with higher user interaction)
3. Decomposition by key customer needs (when form, not the working principle or technology, is the problem)

Find critical subproblems to tackle first
Step 2: Search Externally
= Finding Existing solutions to both overall problem and subproblems
Interview Lead Users
(those who experience needs months or years before the majority of the market and stand to benefit substantially from a product innovation)
Consult Experts
Search Patents
(useful to see what concepts are already protected and must be avoided or licensed)
Search Published Literature
(Journals; Conference proceedings; Trade magazines; Government reports; Market, consumer, and product information; and New product
announcements)
Online search is the best way
Benchmark Related Products
(reveals concepts + strengths and weaknesses of competition, go to Thomas Register website: http://www.thomasglobal.com/)
Step 3: Search Internally


= the use of personal and team knowledge and creativity to generate solution concepts.
Four guidelines:
-
Suspend judgment (= no criticism of concepts) (unlike daily life)
Generate a lot of ideas
Welcome ideas that may seem infeasible
Use graphical and physical media (abundant sketching surfaces)
Both Individual and Group Sessions Can Be Useful
Working alone More and better concepts
Builds concensus
Working together
Communicates information
Refines concepts
Assures spending enough time
Hints for Generating Concepts (for Dummies)
-
Make analogies (think of devices which solve related problems)
Wish and Wonder (“I wish I could …”)
Use related stimuli (=stimuli generated in the context of the problem at hand, like customer need statements and photographs of the use
environment)
Use unrelated stimuli ( like a collection of photos of objects, taking pictures in the streets, a way of cheering up a tired group)
Set qualitative goals (how many ideas to generate)
Use the gallery method (= display a large number of concepts simultaneously for discussion)

Solutions to Subproblem of Storing or Accepting Energy
Self-regulating chemical reaction emitting
High-pressure gas
Carbide (as for lanterns)
Combusting sawdust from job site
Gun powder
Sodium azide (air bag explosive)
Fuel-air combustion (butane, propane, acetylene, etc.)
Compressed air (in tank or from compressor)
Carbon dioxide in tank
Electric wall outlet and cord
High pressure oil line (hydraulics)
Flywheel with charging (spin-up)
Battery pack on tool, belt, or floor
Fuel cell
Solutions to Subproblem of Applying Translational Energy to Nail
Single impact
Multiple impacts
(tens or hundreds)
Multiple impacts
(hundreds or thousands)
Human power; arms or legs
Methane from decomposing organic materials
“burning” like that of chemical hand warmers
Nuclear reactions
Cold fusion
Solar electric cells
Solar-steam conversion
Steam supply line
Wind
Geothermal
Push
Twist-push
Step 4: Explore Systematically
Internal
Search

Concept fragments
(Solutions to Subproblems)
Extenal Search
There are two tools for combining concepts:
Concept Classification Tree
(which divides the possible solutions into independent categories)

Four benefits of the concept classification tree:
1.
2.
3.
4.
Pruning of less promising branches (like nuclear energy for the nailer)
Identification of independent approaches to the problem (reduces complexity, engenders healthy competition among the approaches)
Exposure of inappropriate emphasis on certain branches (too little effort on hydraulic energy for the nailer)
Refinement of the problem decomposition for a particular branch

Chemica
l
Pneumati
c
Store or
Accept
Energy
Fuel-Air
Systems
Explosive
Systems
Hydraul
ic
Wall
Outlet
Electrica
l
Nuclear
Battery
Fuel Cell
Concept Combination Table
(=Potential solutions to the overall problem are formed by combining one fragment from each column.)
- It is simply a way to make forced associations among fragments in order to stimulate further creative thinking.
- In no way does the mere act of selecting a combination yield a complete solution.

Convert Electrical Energy to
Translational Energy
Accumulate Energy
Apply Translational Energy to Nail
………………..
Rotary motor with
transmission
Rotary motor with
transmission
Single impact
Linear Motor
Moving mass
Multiple impacts
Solenoid
……………….
Push nail
Rail gun
……………….
……………….
Convert Electrical Energy to
Translational Energy
Accumulate Energy
Apply Translational Energy to Nail
Rotary motor with
transmission
Rotary motor with
transmission
Single impact
Linear Motor
Moving mass
Multiple impacts
Solenoid
Rail gun
Push nail
……………….
Convert Electrical Energy to
Translational Energy
Accumulate Energy
Apply Translational Energy to Nail
Rotary motor with
transmission
Rotary motor with
transmission
Single impact
Linear Motor
Moving mass
Multiple impacts
Solenoid
Push nail
Rail gun
Convert Electrical Energy to
Translational Energy
Accumulate Energy
Apply Translational Energy to Nail
Rotary motor with
transmission
Rotary motor with
transmission
Single impact
Linear Motor
Moving mass
Multiple impacts
Solenoid
Rail gun
Push nail
Convert Electrical Energy to
Translational Energy
Accumulate Energy
Apply Translational Energy to Nail
Rotary motor with
transmission
Rotary motor with
transmission
Single impact
Linear Motor
Moving mass
Multiple impacts
Solenoid
Push nail
Rail gun

Two guidelines to make concept combination easier
-
Eliminate a fragment if it sounds infeasible before combining (this reduces the number of combinations dramatically)
The concept combination table should be concentrated on the subproblems that are coupled (= subproblems whose solutions can only
be evaluated together.)


Independent solutions can be excluded from the table.
Concept combination tables lose their usefulness when the number of columns exceeds three or four.
Managing the Exploration Process


Rarely teams generate only one classification tree and one concept combination table
Narrow the range of alternatives for the critical subproblems.
Step 5: Reflect on the Solutions and the Process
-
Is the team developing confidence that the solution space has been fully explored?
Are there alternative function diagrams?
Are there alternative ways to decompose the problem?
Have external sources been thoroughly pursued?
Have ideas from everyone been accepted and integrated in the process?
CHAPTER EIGHT
Concept Selection



=the process of evaluating concepts with respect to customer needs and other criteria, comparing the relative strengths and weaknesses
of the concepts, and selecting one or more concepts for further investigation, testing, or development.
Concept selection is convergent but usually iterative
Different methods for choosing a concept:
-
External decision (customer, client, …)
Product champion (an influential member)
Intuition (chosen by its feel, no explicit criteria)
-
Multivoting
Pros and cons (lists of strengths and weaknesses)
Prototype and test
Decision matrices (used in this book)
A structured method

Benefits:
-
A customer-focused product
A competitive design
Better product-process coordination
Reduced time to product introduction
Effective group decision making
Documentation of the decision process
Overview:
-
Concept screening (= a quick, approximate evaluation aimed at producing a few viable alternatives)
Concept scoring (= a more careful analysis of these relatively few concepts to choose one for further development)
Both stages have six steps:
1.
2.
3.
4.
5.
6.
Prepare the selection matrix
Rate the concepts
Rank the concepts
Combine and improve the concepts
Select one or more concepts
Reflect on the results and the process

The concept selection method exploits the matrices as visual guides for consensus building among team members.
Concept Screening
(developed by late stuart pugh)
Step 1: Prepare the Selection Matrix

Selection Criteria
Ease of handling
Ease of use
Readability of settings
Dose metering accuracy
Durability
Ease of manufacture
Portability
…………………….
…………………….
Sum +’s
Sum 0’s
Sum –‘s
Net Score
Rank
Continue?
A
Master
Cylinder
0
0
0
0
0
+
+
B
Rubber
Brake
0
0
0
0
0
2
5
0
2
1
Yes
1
4
2
-1
6
No
Concepts
E
Swash
Ring
0
0
+
0
0
+
F
G
H
I
Ratchet
+
0
0
0
D
(Reference)
Plunge Stop
0
0
0
0
0
0
0
Lever Set
+
0
0
+
0
Dial Screw
0
+
0
0
0
0
…………..
……………
1
3
3
-2
7
No
0
7
0
0
3
Combine
2
4
1
1
2
Yes
2
3
2
0
3
Combine
1
5
1
0
3
Revise
C

-
Concepts should be at the same level of detail
Concepts best portrayed by both written description and graphical representation
The criteria are expressed at a fairly high level of abstraction and typically include from 5 to 10 dimensions.
The team chooses a concept to become the benchmark, or reference concept, against which all other concepts are rated.
Step 2: Rate the Concepts

Relative scores:
Relative scores
+
Better than
0
Same as
Worse than
- Concepts are rated in comparison to the reference concept
- Rate one criterion at a time for all concepts
- Use objective metrics if possible
Step 3: Rank the Concepts

Step 4: Combine and Improve the Concepts

-
Consider if there are ways to combine and improve certain concepts.
Is there a generally good concept which is degraded by one bad feature?
Are there two concepts which can be combined to preserve the “better than” qualities while annulling the “worse than” qualities?
Step 5: Select One or More Concepts

Decide which concepts are to be selected for further refinement and analysis
Step 6: Reflect on the Results and the Process

All of the team members should be comfortable with the outcome.
Concept Scoring
Step 1: Prepare the selection matrix

-
Choose a reference concept
A computer spreadsheet is the best format for the matrix
Concepts expressed in more detail
More criteria used (ease of use=ease of injection+ ease of cleaning+ ease of loading)
Assign importance weights to the matrix (often determined by team consensus)
Weight
Selection Criteria
Ease of handling
Ease of use
Readability of
settings
Dose metering
accuracy
Durability
Ease of manufacture
Portability
…………………….
5%
15%
10%
A
(Reference)
Master Cylinder
Weighted
Rating
Score
3
0.15
3
0.45
Concept
E
DF
Lever Stop
Weighted
Rating
Score
3
0.15
4
0.6
Swash Ring
Weighted
Rating
Score
4
0.2
4
0.6
2
0.2
3
0.3
5
0.5
3
2
3
3
0.75
0.3
0.6
0.3
3
5
3
3
0.75
0.75
0.6
0.3
2
4
2
3
0.5
0.6
0.4
0.3
25%
15%
20%
10%
G+
……………….
Dial Screw +
Weighted
Rating
Score
4
0.2
3
0.45
5
0.5
……………….
Weighted
Rating
Score
3
0.75
3
2
3
0.45
0.4
0.3
…………………….
Total
Score
Rank
Continue?
2.75
4
No
3.45
1
Develop
3.10
2
No
Step2: Rate the Concepts

-
One criteria at a time for all the concepts
Use a scale from 1 to 5:
1
2
3
4
5
-
Relative scores
Much worse than the reference
Worse than the reference
Same as the reference
Better than reference
Much better than reference
Use different reference points for the various selection criteria to avoid “scale compression”
Step 3: Rank the Concepts

The total score for each concept is the sum of the weighted scores
Step 4: Combine and Improve the Concepts

Combine strengths, leave out weaknesses
3.05
…………..
3
No
…………..
…………..
Step 5: Select One or More Concepts

-
Conduct a sensitivity analysis, using a computer spreadsheet, by varying the weights and ratings to determine their effect on the ranking
You may select a lower-scoring concept with less uncertainty over a higher-scoring concept with more uncertainty
Step 6: Reflect on the Result and the Process

-
This is somehow the “point of no return” for the development process
Revisit the dropped concepts and see if they are better overall. Find the source of inconsistency
This matrix was created and used by a development team designing a collar to hold weights onto a barbell.
CHAPTER SIX
Product Specifications (Part two)
Setting the Final Specifications (Page 103)

-
Specifications which originally were only targets expressed as broad ranges of values are now refined and made more precise
Trade offs make it difficult (technical performancecost)
Step 1: Develop Technical Models of the Product

-
Technical model = a tool for predicting the values of the metrics for a particular set of design decisions
Models = both analytical and physical approximations
Analytical modeling is less expensive
Using these models the team can predict whether any particular set of specifications (such as the ideal target values) is technically
feasible by exploring different combinations of design variables
A technical model is almost always unique to a product concept
Step 2: Develop a Cost Model of the Product

-
(The goal is to make sure that the product can be produced at the target cost.)
The appendix to this chapter provides an explanation of target costing.
Manufacturing cost = purchasing or fabrication cost for all parts + assembly and other manufacturing costs
Component
steertube
Crown
Boot
Lower tube
Lower tube top cover
Main lip seal
Slide bushing
Slide bushing spacer
Lower tube plug
Upper tube
Upper tube top cap
Upper tube adjustment knob
Adjustment shaft
Spring
Upper tube orifice cap
Orifice springs
Brake studs
Brake brace bolt
Brake brace
Oil (liters)
Misc. snap rings, o-rings
Decals
Assembly (minutes) at $20/hr
Overhead at b25% of direct cost
Total
Qty/ High Low High Total
Fork ($ea.) ($ ea.) ($/fork)
1
1
2
2
2
2
4
2
2
2
2
2
2
2
1
4
2
2
1
0.1
10
4
2.50
4.00
1.00
3.00
2.00
1.50
0.20
0.50
0.50
5.50
3.00
2.00
4.00
3.00
3.00
0.50
0.40
0.25
5.00
2.50
0.15
0.25
30
2.00
3.00
0.75
2.00
1.50
1.40
0.18
0.40
0.35
4.00
2.50
1.75
3.00
2.50
2.25
0.40
0.35
0.20
3.50
2.00
0.10
0.15
20
$
Low Total
($/fork)
2.50
4.00
2.00
6.00
4.00
3.00
0.80
1.00
1.00
11.00
6.00
4.00
8.00
6.00
3.00
2.00
0.80
0.50
5.00
0.25
1.50
1.00
10.00
20.84
104.19 $
2.00
3.00
1.50
4.00
3.00
2.80
0.72
0.80
0.70
8.00
5.00
3.50
6.00
5.00
2.25
1.60
0.70
0.40
3.50
0.20
1.00
0.60
6.67
15.73
78.67
Step 3: Refine the Specifications, Making Trade-offs Where Necessary

-
Finalizing the specifications can be accomplished in a group session in which feasible combinations of values are determined through
the use of technical models and then the cost implications are explored.
In an iterative fashion, the team converges on the specifications that will most favorably position the product relative to the competition,
will best satisfy the customer needs, and will ensure adequate profits.
Competitive maps can be constructed from competitive benchmarking chart.
The competitive map is used to position the new product relative to the competition
Technical Model
+
Cost Model
+
Competitive Map
Final Specifications
No.
Metric
Unit
1
2
3
4
5
6
7
8
9
10
Attenuation from dropout to handlebar at 10 Hz
Spring preload
Maximum value from the Monster
Minimum descent time to test track
Damping coefficient adjustment range
Maximum travel (26-in. wheel)
Rake offset
Lateral stiffness at brake pivots
Total mass
Lateral stiffness at the tip
dB>
N
g
s
N-s/m
mm
mm
kN/m
kg
kN/m
11
Headset sizes
in.
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Steer tube length
Wheel sizes
Maximum tire width
Time to assemble to frame
Fender compatibility
Instills pride
Unit manufacturing cost
Time in spray chamber without water entry
Cycles in mud chamber without contamination
Time to disassemble/assemble for maintenance
Special tools required for maintenance
UV test duration to degrade rubber parts
Monster cycles to failure
Japan Industrial Standards test
Bending strength (frontal loading)
mm
List
in.
s
List
Subj.
US$
s
k-cycles
s
List
hr
Cycles
Binary
kN
Value
12
600-650
<3.4
<11.5
>100
43
38
>75
<1.4
>425
1
1.125
150
170
190
210
230
26 in.
>1.75
<45
Zefal
>4
<80
>3600
>25
<200
Hex
>450
>500k
Pass
>10.0
Step 4: Flow Down the Specifications as Appropriate
Flow down the overall specifications to specifications for subsystems
Step 5: Reflect on the Result and the Process

-
Is the product a winner?
How much uncertainty is there in the technical and cost models?
Is the concept chosen by the team best suited to the target market, or could it be best applied in another market?
Should the firm initiate a formal effort to develop better technical models of some aspects of the product’s performance for future use?
Appendix
Target Costing

=use the value of the manufacturing cost specification based on the price the company hopes the end user will pay for the product and on
the profit margins that are required for each stage in the distribution channel.
Target costing is the reverse of the cost-plus approach to pricing.
M: gross profit mrgin of a stage in the distribution channel.

M 
(P  C)
P
P: the price this stage charges its customers
C: the cost this stage pays for the product it sells
Then

C: Target Cost
n
C  P (1  M i )
i 1
Where:
P: the price paid by the end user
N: the number of stages in the distribution channel
M i :the margins of the ith stage