Transcript Document

Product Design & Development
Product Specifications
1
July 18, 2015
Product Design and Development - Chapter 5
What are specifications?
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
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Specifications spell out in precise, measurable
detail what the product has to do.
Specifications represent an unambiguous
agreement on what the team will attempt to
achieve in order to satisfy the identified
customer needs.
Must include regulatory and agency approval
requirements
July 18, 2015
Product Design and Development - Chapter 5
Concept Development Process
Mission
Statement
Identify
Customer
Needs
Establish
Target
Specifications
Generate
Product
Concepts
Select
Product
Concept(s)
Test
Product
Concept(s)
Set
Final
Specifications
Plan
Downstream
Development
Development
Plan
Perform Economic Analysis
Benchmark Competitive Products
Build and Test Models and Prototypes
3
Target Specs
Final Specs
Based on customer needs
and benchmarking
Based on selected concept,
feasibility, models, testing,
and trade-offs
July 18, 2015
Product Design and Development - Chapter 5
Product specifications

Other names for ‘product specifications’
–
–
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Product requirements
Technical specifications
July 18, 2015
Product Design and Development - Chapter 5
Product Specifications Example:
Mountain Bike Suspension Fork
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July 18, 2015
Product Design and Development - Chapter 5
A specification

A ‘specification’ (sing.) consists of a metric and
a value
Example:
metric  “Average time to assemble”
value  “less than 75 seconds”
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July 18, 2015
Product Design and Development - Chapter 5
When are specs established?
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
For simple products (e.g., soap):
early in the development process, right after
identifying customer needs
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For technology-intensive products:
at least twice …
July 18, 2015
Product Design and Development - Chapter 5
For technology-intensive products

Target specifications
–

Refined specifications
–
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(representing hopes and aspirations)
are set immediately the team has identified the
customer needs it aims to meet.
(i.e., the specs the team aims to achieve)
are documented in the project´s “contract book”.
July 18, 2015
Product Design and Development - Chapter 5
Target specifications
To establish target specs:
 Prepare list of metrics, using the needs/metrics
matrix.
 Collect benchmarking information.
 Set ideal and marginally acceptable target
values for each metric.
 Reflect on results and process.
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July 18, 2015
Product Design and Development - Chapter 5
Metrics

Prepare a list of metrics
The underlying assumption is that consumer needs
can be translated into precise, measurable specs
and that meeting specs will result in satisfaction of
the associated customer needs.
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July 18, 2015
Product Design and Development - Chapter 5
The Product Specs Process
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Set Target Specifications
–
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–
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Refine Specifications
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Based on selected concept and feasibility testing
Technical modeling
Trade-offs are critical
Reflect on the Results and the Process
–
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Based on customer needs and benchmarks
Develop metrics for each need
Set ideal and acceptable values
Critical for ongoing improvement
July 18, 2015
Product Design and Development - Chapter 5
Start with the Customer Needs
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The suspension
The suspension
The suspension
The suspension
The suspension
The suspension
The suspension
The suspension
The suspension
The suspension
The suspension
The suspension
The suspension
The
suspension
July
18, 2015
NEED
Im p
reduces vibration to the hands.
3
•
allows easy traversal of slow, difficult terrain.
2
••
enables high speed descents on bum py trails.
5
•
allows sensitivity adjustm ent.
3
•
preserves the steering characteristics of the bike. 4 ••••
rem ains rigid during hard cornering.
4
•
is lightweight.
4
•
provides stiff mounting points for the brakes.
2
•
fits a wide variety of bikes, wheels, and tires.
5 ••••
is easy to install.
1 ••••
works with fenders.
1
•••
instills pride.
5
•
is affordable for an amateur enthusiast.
5 ••••
is not contam inated
by water.
5 5 •
Product
Design and Development - Chapter
… but remember
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Metrics should be dependent, NOT
independent, variables.
Metrics should be practical.
Some needs cannot be easily translated into
quantifiable metrics (subjective needs).
Metrics should include popular criteria used for
‘marketplace’ comparisons.
July 18, 2015
Product Design and Development - Chapter 5
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Need #s
Metric #
Establish Metrics and Units
Metric
Imp
Units
1,3 Attenuation from dropout to handlebar at 10hz
3
dB
2,6 Spring pre-load
3
N
1,3 Maximum value from the Monster
5
g
1,3 Minimum descent time on test track
5
s
4 Damping coefficient adjustment range
3 N-s/m
5 Maximum travel (26in wheel)
3
mm
5 Rake offset
3
mm
6 Lateral stiffness at the tip
3 kN/m
7 Total mass
4
kg
8 Lateral stiffness at brake pivots
2 kN/m
9 Headset sizes
5
in
9 Steertube length
5
mm
9 Wheel sizes
5
list
9 Maximum tire width
5
in
10 Time to assemble to frame
1
s
11 Fender compatibility
1
list
July
2015 pride
Product Design and Development
1218,
Instills
5 - Chapter
subj 5
Metrics Exercise:
Ball Point Pen

Customer Need:
–

Metric(s):
1.
2.
3.
4.
5.
6.
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The pen writes smoothly.
Variation in line thickness (mm)
Variation in ink coverage (cc/mm2)
Functional range of writing force (N)
Functional range of writing velocity
(mm/sec)
Functional range of pen angle from
vertical (deg)
Variation in resistance to translational
motion (N)
July 18, 2015
Assuming that smooth writing
can be characterized by:
• Good quality line
• Preservation of line quality
• Ease of use...
Product Design and Development - Chapter 5
Needs vs. Metrics
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July 18, 2015
Product Design and Development - Chapter 5
Benchmarking

No product development team can expect to
succeed without ‘benchmarking’ the project
against competing products
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17
Warning: Data in competitors’ catalogues and
supporting literature may not be accurate. Values for
key metrics should be verified by independent
testing and observation.
July 18, 2015
Product Design and Development - Chapter 5
1
2
3
4
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6
7
8
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10
11
12
1,3
2,6
1,3
1,3
4
5
5
6
7
8
9 Headset sizes
9 Steert ube lengt h
5
5
in
mm
8
15
10
15
9
550
760
500
710
480
3.6
3.2
3.7
3.3
3.7
13 11. 3
12. 6 11. 2
13. 2
0
0
0
200
0
28
48
43
46
33
41. 5
39
38
38
43. 2
59
110
85
85
65
1.409 1.385 1.409 1.364 1.222
295
550
425
425
325
1.000
1.000
1.000 1.125 1.000 1.125 1.000
1.125 1.250 1.125 1.250 1.125
150
180
210
230
255
140
165
190
215
150
170
190
210
150
170
190
210
230
150
190
210
220
Gunhill Head Shox
Tonka Pro
Rox Tahx Ti 21
Rox Tahx Quadra
Unit s
dB
N
g
s
N-s/m
mm
mm
kN/ m
kg
kN/ m
Maniray 2
Metric
Im p
Att enuati on from dropout t o handlebar at 10hz 3
Spri ng pre-load
3
Maximum val ue from the Monster
5
Mi ni mum descent tim e on test t rack
5
Damping coef fi ci ent adjust ment range
3
Maximum travel (26in wheel)
3
Rake of fset
3
Lateral st if fness at the ti p
3
T otal mass
4
Lateral st if fness at brake pi vots
2
ST Tritrack
Need #s
Metric #
Benchmark on Metrics
13
680
3.4
11
0
38
39
130
1.1
650
NA
NA
26in
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14
15
16
17
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19
20
18
9
9
10
11
12
13
14
15
Wheel sizes
Maximum tire widt h
T im e to assemble to f rame
Fender compati bili ty
Insti lls pri de
Unit manufact uring cost
T im e in spray chamber w/o wat er entry
18,
2015
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all
subj
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Product
Development
535
k-cyclesDesign
15 and19
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18
19
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••••
••••• •••• •••• Development
Gunhill Head Shox
Tonka Pro
Rox Tahx Ti 21
Rox Tahx Quadra
NEED
Im p
The suspension reduces vibration to the hands.
3
•
The suspension allows easy traversal of slow, difficult terrain.
2
••
The suspension enables high speed descents on bum py trails.
5
•
The suspension allows sensitivity adjustm ent.
3
•
The suspension preserves the steering characteristics of the bike. 4
••••
The suspension rem ains rigid during hard cornering.
4
•
The suspension is lightweight.
4
•
The suspension provides stiff mounting points for the brakes.
2
•
The suspension fits a wide variety of bikes, wheels, and tires.
5
••••
The suspension is easy to install.
1
••••
The suspension works with fenders.
1
•••
The suspension instills pride.
5
•
The suspension is affordable for an amateur enthusiast.
5 •••••
The suspension is not contam inated by water.
5
•
The suspension is not contam inated by grunge.
5
•
The suspension
be easily accessed for maintenance.
3
••••
July 18, can
2015
Product Design
and
Maniray 2
#
1
2
3
4
5
6
7
8
9
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11
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15
16
ST Tritrack
Benchmark on Customer Needs
••
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••• •••••
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••• •••••
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•••••
•5
Chapter
Setting target values

Set ideal and marginally acceptable target
values for each metric.
–
–
–
–
–
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At least X
At most X
Between X and Y
Exactly X
A set of discrete values
July 18, 2015
Product Design and Development - Chapter 5
1
2
3
4
5
6
7
8
9
10
in
11 Headset sizes
21
>15
>10
480 - 800 650 - 700
<3.2
<3.5
<11.0
<13.0
>200
0
45
33 - 50
38
37 - 45
>130
>65
<1.1
<1.4
>650
>325
1.000
1.125
1.000
1.250
1.125
150
170
190
210
230
mm
26in
700c
26in
list
>1.75
>1.5
in
<35
<60
s
all
none
list
>5
>3
subj
andUS$
Development<85
- Chapter<65
5
150
170
190
210
12 Steertube length
13 Wheel sizes
14 Maximum tire w idth
15 Time to assemble to f rame
16 Fender compatibility
17 Instills pride
July
18, 2015
18 Unit manuf acturing cost
Units
dB
N
g
s
N-s/m
mm
mm
kN/m
kg
kN/m
Product Design
Ideal Value
Metric
Attenuation from dropout to handlebar at 10hz
Spring pre-load
Maximum value f rom the Monster
Minimum descent time on test track
Damping coef ficient adjustment range
Maximum travel (26in w heel)
Rake of fset
Lateral stif fness at the tip
Total mass
Lateral stif fness at brake pivots
Marginal Value
Assign Marginal and Ideal Values
Refining the specs
(at the end of the Concept Development phase)
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Develop technical models of product.
Develop cost model.
Refine specs, making trade-offs where
necessary.
Base trade-offs on tests using technical models
and preliminarily cost model.
Reflect on results and process.
July 18, 2015
Product Design and Development - Chapter 5
Technical models
Develop technical models of the product:
 A technical model is a tool for predicting the
values of different metrics for a particular set of
design decisions.
–
23
As used here, a ‘model’ may be an analytical or
physical approximation of the product.
July 18, 2015
Product Design and Development - Chapter 5
24
July 18, 2015
Product Design and Development - Chapter 5
Cost model
Develop a cost model of the product:
 Goal is to make sure product can be produced
at a reasonable cost.
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July 18, 2015
Product Design and Development - Chapter 5


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How much uncertainty is there in the technical
and cost models?
Is concept chosen by team best for target
market, or might it be more suitable for another
market or segment (low-end or high-end
instead of middle?)
July 18, 2015
Product Design and Development - Chapter 5

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Should the firm initiate a formal effort to
develop better technical models of some
aspect of product performance for future use?
July 18, 2015
Product Design and Development - Chapter 5
Specification Trade-offs
Estimated Manufacturing Cost ($)
Trade-off Curves
for Three Concepts
Score on Monster (Gs)
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July 18, 2015
Product Design and Development - Chapter 5
Crunch
Perceptual Mapping Exercise
KitKat
Nestlé
Crunch
Opportunity?
Hershey’s
w/ Almonds
Hershey’s
Milk Chocolate
Chocolate
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July 18, 2015
Product Design and Development - Chapter 5
Set Final Specifications
1
2
3
4
5
6
7
8
9
10
METRI C
Att enuat ion f rom dropout t o handlebar at 10hz
Spring pre-load
Maximum v alue f rom t he Mons ter
Minimum desc ent t ime on tes t t rac k
Damping c oef f icient adjus tment range
Maximum trav el (26in wheel)
Rake of f s et
Lat eral s tif f nes s at t he t ip
Tot al mas s
Lat eral s tif f nes s at brak e piv ot s
11 Heads et s izes
30
12 Steertube lengt h
13 Wheel s izes
14 Maximum tire width
15 Time t o as s emble t o f rame
16 Fender c ompat ibilit y
17 Ins tills pride
July 18,18
2015
Unit manuf ac turing c ost
Units
dB
N
g
s
N-s/m
mm
mm
kN/m
kg
kN/m
Val ue
>12
650
<3.4
<11.5
>100
43
38
>75
<1.4
>425
1.000
in
1.125
150
170
190
210
mm
230
li st
26in
in
>1.75
s
<45
li st
Zefal
subj
>4
Product Design and Development
- Chapter
US$
<805
Quality Function Deployment
(House of Quality)
technical
correlations
relative
importance
customer
needs
engineering
metrics
benchmarking
on needs
relationships between
customer needs and
engineering metrics
target and final specs
31
July 18, 2015
Product Design and Development - Chapter 5
Reflect on results and process
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Are team members ‘gaming’?
Should team consider offering multiple
products?
Are any specification missing?
July 18, 2015
Product Design and Development - Chapter 5
Reflect on results and process
Is the product a winner?
–
–
–
33
Product concept should allow team to see specs in a way that
the price will meet the customer needs and excel competitively.
Product concept + specs should offer prospect of competitive
pricing + performance meeting or exceeding customer needs
If not, return to concept generation and selection phase or
abandon project.
July 18, 2015
Product Design and Development - Chapter 5