Product Specifications

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Product Specifications

• Chapter 5
• EIN 6392, Spring 2008
• Product Design for Manufacturability and
  Automation

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Product Design and DevelopmentKarl T. Ulrich and
Steven D. Eppinger

• 1. Introduction
• 2. Development Processes and Organizations
• 3. Product Planning
• 4. Identifying Customer Needs
• 5. Product Specifications
• 6. Concept Generation
• 7. Concept Selection
• 8. Concept Testing
• 9. Product Architecture
• 10. Industrial Design
• 11. Design for Manufacturing
• 12. Prototyping
• 13. Product Development Economics
• 14. Managing Projects

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

• Nature of specifications
• Spec vs. specs.
• Target vs. refined specs.
• Process for setting target specs
• Process for setting final specs

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Spec vs. Specs

• A spec consists of a metric and a value
• Specs is a set of specs.

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Target vs. refined specs

• Target specs the hopes and aspirations of the
  design (ideal and marginal)
• Refined specs trade-offs among different desired
  characteristics.
• Intermediate specs
• Final specs
• It is in the projects contract book

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Nature of Specifications

• The reference point of the design
• A reference for functionality design and quality
  planning
• It may consist of a hierarchy of specs for the
  final product as well as its components

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Process for establishing target specifications

• Identify a list of metrics and measurement units
  that sufficiently address the needs
• Collect the competitive benchmarking information
• Set ideal and marginal acceptable target values
  for each metric (at least, at most, between,
  exactly, etc.)
• Reflect on the results and the process

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Process for setting the final specifications

• Develop technical models to assess technical
  feasibility. The input is design variable and
  the output is metric.
• Develop a cost model of the product.
• Refine the specifications, marking the tradeoffs
  where necessary to form a competitive map.
• Flow down the final overall specs to specs for
  each subsystem
• Reflect on the results to see
• If the product is a winner and/or
• How much uncertainty there is in the technical
  and cost model.
• If there is a need to develop a better technical
  model.

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Product Specifications ExampleMountain Bike
Suspension Fork
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Start with the Customer Needs
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Establish Metrics and Units
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Link Metrics to Needs
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Benchmark on Customer Needs
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Benchmark on Metrics
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Assign Marginal and Ideal Values
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Concept Development Process
Mission Statement
Development Plan
Identify Customer Needs
Establish Target Specifications
Generate Product Concepts
Select Product Concept(s)
Set Final Specifications
Plan Downstream Development
Test Product Concept(s)
Perform Economic Analysis
Benchmark Competitive Products
Build and Test Models and Prototypes
Target Specs Based on customer needs and
benchmarking
Final Specs Based on selected concept,
feasibility, models, testing, and trade-offs
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Perceptual Mapping Exercise
Opportunity?
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Specification Trade-offs
Estimated Manufacturing Cost ()
Score on Monster (Gs)
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Set Final Specifications
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Quality Function Deployment(House of Quality)
technical correlations
relative importance
engineering metrics
benchmarking on needs
customer needs
relationships between customer needs
and engineering metrics
target and final specs
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Chapter 5 HW

• Metrics Exercise Ball Point Pen
• Write down 5 possible metrics for the customer
  need
• The pen writes smoothly.