Design Problem Formulation

1
Design Problem Formulation

• Customer Requirements
• Company Requirements
• QFD/House of Quality
• Eng. Design Specifications
• Gaining consensus
• Key terms / tests

2
Formulating (a design problem)
Initial design problem description
Formulating process
Literature, Surveys Market Studies Focus
Groups Observation Studies Benchmark Studies
Customer needs? Competition?
Seek info
Functional requirements? Targets?
Constraints? Evaluation criteria?
Interpret Summarize
probe
revise
Gain consensus
Preliminary design specifications
Review
discontinue
Obtain management approval
continue
principal output
Engineering Design Specification
3
How do we formulate a design problem?

• 1. obtain a detailed understanding of the design
  problem
• 2. document our understanding in an EDS
• 3. choose a solution strategy
• 4. develop a project plan (scope of work, budget
  and schedule)
• 5. establish a consensus among team members
  management

4
What is a detailed understanding?

• Customer and company requirements
• Importance weights
• Engineering characteristics, units, limits
• Constraints on function or form
• Satisfaction tables/curves

by all team members
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Customer requirements
Other Economic Geometry Maintenance
Repair Retirement Reliability Robustness Safety
Pollution Ease of use Human Factors Appearance
Function / performance Functions /
Importance Engineering characteristics
(units, limits) Performance Targets
Satisfactions
Operating Environment Air temp., humidity,
pressure Contaminants Shock, vibration
Note the deliberate absence of form attributes
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Company Requirements
Manufacturing Production quantity Processes,
Materials New factory equip. Warehousing dist.
Financial Product Development Investment Return
on investment Other Regulations, Standards,
Codes Patents / intellectual property
Marketing Customer/Consumer Competition Strategy
Time to market Pricing Advertising Sales demand,
targets
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Motorcycle Importance of each requirement

• Customer importance weights by sub-function
• Sub-function Weight
• start engine quickly 15
• support rider(s) comfortably 10
• transport rider(s) fast 50
• steer bike easy 20
• absorb road shocks 5
• total 100

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Engineering characteristics, units, and limits
Quantities that measure the performance of a
candidate design (with respect to specific
customer required functions).
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Satisfaction as a function of Top Speed (mph).

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How can we systematically develop all that
information to assure QUALITY?

• Maintain a good set of notes

• Prepare a House of Quality
• With team members
• 2-D matrix of information
• Facilitates group discussions
• Forces agreement of targets/data

 
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Example HoQpencil sharpener
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Engineering Design Specification template
Table 3.2 Engineering Design Specification
template.          
Table 3.2 Engineering Design Specification
template.          
    Table 3.2 Engineering Design Specification
template.                              
    Table 3.2 Engineering Design Specification
template.                              
Cover page (title, stakeholders, and
date) Introduction Simple description of design
problem (Un)intended purpose(s) or use(s) of the
product Special features Customer and Company
requirements Engineering characteristics,
units, limits Customer satisfaction Constraints A
ppendices
(See coffee maker example for more details)
Cover page title, stakeholders, and
date Introduction Simple description of design
problem Intended purpose(s) or use(s) of the item
to be designed Special features Customer
requirements (see section 3.3.1) Engineering
characteristics Constraints Customer
satisfaction Company requirements (see section
3.3.2) Engineering characteristics Constraints Cus
tomer satisfaction
Cover page title, stakeholders, and
date Introduction Simple description of design
problem Intended purpose(s) or use(s) of the item
to be designed Special features Customer
requirements (see section 3.3.1) Engineering
characteristics Constraints Customer
satisfaction Company requirements (see section
3.3.2) Engineering characteristics Constraints Cus
tomer satisfaction
Cover page title, stakeholders, and
date Introduction Simple description of design
problem Intended purpose(s) or use(s) of the item
to be designed Special features Customer
requirements (see section 3.3.1) Engineering
characteristics Constraints Customer
satisfaction Company requirements (see section
3.3.2) Engineering characteristics Constraints Cus
tomer satisfaction
Cover page title, stakeholders, and
date Introduction Simple description of design
problem Intended purpose(s) or use(s) of the item
to be designed Special features Customer
requirements (see section 3.3.1) Engineering
characteristics Constraints Customer
satisfaction Company requirements (see section
3.3.2) Engineering characteristics Constraints Cus
tomer satisfaction
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Formulation initiates all solution strategies.
 
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Step 4. Project Planning
Formulating a design problem
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Step 5. Establish a consensus of opinion
Formulating a design problem

• 1. obtain a detailed understanding of the design
  problem,
• 2. document our understanding in an EDS
• 3. choose a solution strategy
• 4. develop a project plan
• 5. establish a consensus among team members
  management

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Getting consensus is built-in
If our team members follow the previous five
steps to a sound formulation, we will

• Have a common understanding of the problem,
• Understand WHY,
• Know WHAT has to be done and WHEN, and
• Commit to WHO HOW MUCH

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Secret for a successful solution
is a .
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Summary

• Customer/Company Requirements
• House of Quality for product planning
• Quality Function Deployment
• Engineering Design Specifications
• Gaining consensus