ECE362 Principles of Design

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ECE362Principles of Design

• Conceptual and Detail Design

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High Level Design
Stage 1 Needs, System Definition, PDS or
Requirements Specification
Needs and Marketing
System Definition
Requirements Specifications
High Level Design
Conceptual Design
Detail Design
Stage 2 Design
Test
Reporting
Verification
Stage 3 Test, Verification, Reporting
Manufacturing
Stage 4 Manufacturing, Sales, Distribution
Sales
Distribution
This process is part of what we call Systems
Engineering
Deliver Product
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Conceptual Design
Generate ideas about HOW to fulfill the PDS. What
materials, technologies and processes will be
used? Will you use a tried and true approach or
will you try a potentially revolutionary, yet
unproven, approach? Evaluate ideas Pugh Matrix
Method
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Evaluation of Ideas

• Evaluation Criteria are established before any
  evaluations are made.
• Evaluation Criteria come from the PDS.
• Evaluation Criteria are unambiguous.
• Evaluation Criteria are to evaluate, not to
  optimize different approaches.

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Pugh Matrix Technique I

• Set up a matrix (table) with concepts across the
  columns and criteria across the rows.
• Rate each concept against important evaluation
  criteria (generated from PDS).

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Pugh Matrix Technique II

• Choose a reference concept without any prior
  solution, choose the one the group intuitively
  thinks is the best.
• Enter a PLUS () if a concept is better than the
  datum enter a MINUS (-) if a concept is worse
  than the datum enter an S if a concept is the
  same as the datum.
• Total the PLUSes and MINUSes for each concept and
  obtain the algebraic sum for each concept.

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Evaluation of Ideas Pugh Method
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Pugh Matrix Technique III

• Carefully look at the pattern of MINUSes try to
  generate improvements to the concept without
  eroding the PLUSes.
• If a number of strong concepts do not emerge,
  usually the criteria are ambiguous or subject to
  different interpretations or concepts are
  similar.
• When one concept is strongest, re-run the matrix
  using it as the datum to validate it as the
  strongest.

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Pugh Matrix Technique IV

• Greater insight into the requirements of the PDS.
• Greater understanding of the design problems.
• Greater understanding of the potential solutions.
• Understanding of the interaction between the
  solutions.
• Knowledge of why one concept is stronger or
  weaker than another.
• Natural stimulus to generate other concepts.

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Detail Design

• Specific details are determined.
• The sort of design in individual courses, but
  with interactions between subsystems.
• Subsystems and components must be defined in a
  similar manner to the PDS.
• Generate Component Design Specification (CDS)
  with emphasis on local performance, environment,
  and constraints.
• Primary emphasis is upon performance.