Product development

1. Product Specifications

2. Product Design and Development
Karl T. Ulrich and Steven D. Eppinger
5th edition, Irwin McGraw-Hill, 2012.
Chapter Table of Contents:
1. Introduction
2. Development Processes and Organizations
3. Opportunity Identification
4. Product Planning
5. Identifying Customer Needs
6. Product Specifications
7. Concept Generation
8. Concept Selection
9. Concept Testing
10. Product Architecture
11. Industrial Design
12. Design for Environment
13. Design for Manufacturing
14. Prototyping
15. Robust Design
16. Patents and Intellectual Property
17. Product Development Economics
18. Managing Projects

3. 10/2/2023 3
Outline
• Nature of specifications
• Spec vs. specs.
• Target vs. final specs.
• Process for setting target specs
• Process for setting final specs

5. Product Specifications Example:
Mountain Bike Suspension Fork

6. • The development team - spent a great deal of
time identifying customer needs.
• In addition to logging many hours of riding on
suspended bikes themselves,
- interviewed lead users at mountain bike
races and recreational cyclists on local trails
- had spent time working with dealers in their
stores.

7. Start with the Customer Needs
The above needs provide little specific guidance about how to design and engineer the
product.

8. Product Specifications
 Do not tell the team how to address the customer needs
 They do represent an unambiguous agreement on what
the team will attempt to achieve in order to satisfy the
customer needs.
• Product specifications - precise description of what the
product has to do.
• Some firms use “product requirements” or “engineering
characteristics”.
• Other firms use “specifications” or “technical specifications”
- refer to key design variables of the product such as the oil
viscosity or spring constant of the suspension system.

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Spec vs. Specs
• A specification consists of a metric, a unit, and a
value
• For example, “average time to assemble” is a metric,
while “less than 75 seconds” is the value of this
metric.
• Specifications – the set of individual specifications.

10. Concept Development Process
Perform Economic Analysis
Benchmark Competitive Products
Build and Test Models and Prototypes
Identify
Customer
Needs
Establish
Target
Specifications
Generate
Product
Concepts
Select
Product
Concept(s)
Set
Final
Specifications
Plan
Downstream
Development
Mission
Statement Test
Product
Concept(s)
Development
Plan
Target Specs
Based on customer needs
and benchmarking
Final Specs
Based on selected concept,
feasibility, models, testing,
and trade-offs

11. 11
Target vs. Final Specs
• Target specs: the hope and aspiration of the team
(ideal and marginal)
• Refined specs: trade-offs among different desired
characteristics.
– Intermediate specs
• Final specs (One of the Key elements of the
development plan)
- It is in the project’s contract book (specifies what
the team agrees to achieve, the project schedule, the
required resources, and the economic implications for
the business.
In an ideal world, the team would establish the product specifications
once early in the development process and then proceed to design
and engineer the product to exactly meet those specifications.

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Nature of Specifications
• The reference point for functionality
design and quality planning
• A product assembly usually requires a
hierarchy of specs, for the final product
and each of its components

13. Establishing Target specifications
• An arbitrary setting of the specifications may not
be technically feasible.
• Target Specifications are Goals of the
development team, describing a product that the
team believes would succeed in the marketplace.
• Later these specifications will be refined based
on the limitations of the product concept actually
selected.

14. The Product Specs Process
1. Set Target Specifications
– Based on customer needs and benchmarks
– Develop metrics for each need
– Set ideal and acceptable marginal values
2. Refine Specifications
– Based on selected concept and feasibility testing
– Technical and economic modeling
– Trade-offs are critical
3. Reflect on the Results and the Process
– Critical for ongoing improvement

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Procedure for establishing
target specifications
1. Identify a list of metrics and measurement units that
sufficiently address the needs
2. Collect the competitive benchmarking information
3. Set ideal and marginally acceptable target values
for each metric (using at least, at most, between,
exactly, etc.)
4. Reflect on the results and the process

16. Link Metrics to Needs

17. Establish Metrics and Units

18. Guidelines considered when
constructing the list of metrics
Metrics should be complete.
• Ideally each customer need would correspond to a single
metric, and the value of that metric would correlate
perfectly with satisfaction of that need.
• In practice, several metrics may be necessary to
completely reflect a single customer need.
Metrics should be dependent, not independent, variables
• This guideline is a variant of the what-not-how principle

19. Guidelines considered when
constructing the list of metrics
• Metrics should be practical.
Do not provide a metric for a bicycle suspension that can
only be measured by a scientific laboratory at a cost of
$100,000.
• Some needs cannot easily be translated into
quantifiable metrics.
- need (suspension instills pride) may be quite critical
to success in the fashion-conscious mountain bike market,
but how pride be quantified?
• The metrics should include the popular criteria
for comparison in the marketplace

20. Benchmark on Customer Needs
Scoring more “dots” corresponds to greater perceived satisfaction of the need.

21. Benchmark on Metrics

22. Assign Marginal and Ideal Values
The ideal value is the best
result the team could hope for.
The marginally acceptable
value is the value of the metric
that would just barely make the
product commercially viable.

23. Concept Development Process
Perform Economic Analysis
Benchmark Competitive Products
Build and Test Models and Prototypes
Identify
Customer
Needs
Establish
Target
Specifications
Generate
Product
Concepts
Select
Product
Concept(s)
Set
Final
Specifications
Plan
Downstream
Development
Mission
Statement Test
Product
Concept(s)
Development
Plan
Target Specs
Based on customer needs
and benchmarking
Final Specs
Based on selected concept,
feasibility, models, testing,
and trade-offs

24. 10/2/2023 24
Process for setting the final
specifications
1. Develop technical models to assess technical feasibility. The
input is design variable and the output is a measurement using
a metric.
2. Develop a cost model of the product.
3. Refine the specifications, making tradeoffs, where necessary to
form a competitive map.
4. “Flow down” the final overall specs to specs for each
subsystem (component and part).
5. Reflect on the results to see
 Whether the product is a winner, and/or
 How much uncertainty there is in the technical and cost model, or

25. Develop Technical Models of the Product

26. Develop a Cost Model of the Product

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Specification Trade-offs
Score on Monster (Gs)
Trade-off Curves
for Three Concepts
Estimated
Manufacturing
Cost
($)

28. Set Final Specifications

29. • For relatively mature product categories in which competition is
based on performance relative to a handful of well-understood
performance metrics, conjoint analysis may be useful in refining
product specifications.
• Conjoint analysis uses customer survey data to construct a
model of customer preference.
• Essentially each respondent in a sample of potential customers is
repeatedly asked to evaluate hypothetical products characterized
by a set of attributes.
• These attributes must generally be metrics that are easily
understood by customers (e.g., fuel economy and price for
automobiles). Subjective attributes (e.g., styling) can be
represented graphically.
• Using this approach, the specification values that maximize market
share can be estimated.

30. Flow Down the Specifications as
Appropriate
• Developing a highly complex product consisting of multiple
subsystems designed by multiple development teams.
• In such a context, specifications are used to define the
development objectives of each of the subsystems as well as for
the product as a whole.
• One challenge in the flow-down process is to ensure that the
subsystem specifications in fact reflect the overall product
specifications.
Example:
• Fuel efficiency is a relatively complex function of vehicle mass,
rolling resistance, aerodynamic drag coefficient, frontal area,
and engine efficiency.

31. Thank You