Friday, February 12, 2010

Universal Laws for Naive Engineers

Pondering life’s lighter moments and following on from his recent post entitled “The Origins of Murphy’s Law”; Pieter Rautenbach has forwarded us the next installment, “Universal Laws for Naive Engineers”:
  1. In any calculation, any error which can creep in will do so.
  2. Any error in any calculation will be in the direction of most harm.
  3. In any formula, constants ( especially those obtained from engineering handbooks ) are to be treated as variables.
  4. The best approximation of service conditions in the laboratory will not begin to meet those conditions encountered in actual service.
  5. The most vital dimension on any plan or drawing stands the greatest chance of being omitted.
  6. If only one bid can be secured on any project, the price will be unreasonable.
  7. If a test installation functions perfectly, all subsequent production units will malfunction.
  8. All delivery promises must be multiplied by a factor of 2.0 .
  9. Major changes in construction will always be requested after fabrication is nearly completed.
  10. Parts that positively cannot be assembled in improper order will be.
  11. Interchangeable parts won't.
  12. Manufacturer's specifications of performance must be multiplied by a factor of 0.5.
  13. Salespeople's claims for performance should be multiplied by a factor of 0.25 .
  14. Installation and Operating Instructions shipped with the device will be promptly discarded by the Receiving Department.
  15. Any device requiring service or adjustment will be least accessible.
  16. Service Conditions as given on specifications will be exceeded.
  17. If more than one person is responsible for a miscalculation, no one will be at fault.
  18. Identical units which test in an identical fashion will not behave in an identical fashion in the field.
  19. If, in engineering practice, a safety factor is set through service experience at an ultimate value, an ingenious idiot will promptly calculate a method to exceed said safety factor.
  20. Warranty and guarantee clauses are voided by payment of the invoice.
Ernest Roper

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