MEPX
Chapter 2 of 12All chapters
  1. 1What engineers do
  2. 2The design process
  3. 3Forces and loads
  4. 4Stress, strain and materials
  5. 5Structures
  6. 6Mechanisms
  7. 7Electrical basics
  8. 8Energy in machines
  9. 9Manufacturing and tolerances
  10. 10Safety factors and failure
  11. 11Testing and standards
  12. 12Responsibility

Chapter 2 of 12

The design process

A loop, not a line.

The stages

Define the problem, gather requirements, generate options, model and calculate, build a prototype, test it, then revise. The loop runs many times, and the early loops are meant to be cheap.

  • A failed prototype is information, and the earlier it fails the less it costs.
  • Skipping straight to the first idea is the most expensive habit in engineering.

Requirements

Requirements say what the thing must do and how it will be judged, in numbers where possible. Vague requirements produce arguments at the end rather than clarity at the start.