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Industrial Engineering & Manufacturing vocabulary · Process Improvement

5 Whys

Meaning in industrial engineering & manufacturing, with examples

nounCommon term

In industrial engineering & manufacturing, 5 Whys means: A simple root cause technique in which you keep asking 'why?' about a problem, about five times, until you reach a cause you can actually fix.

In Turkish: 5 Neden, 5 Neden analizi

How it is used

Developed within Toyota and used in 8D reports and daily problem solving. Teams do a 5 Whys, ideally on the shop floor with the people involved. Five is a guide, not a rule, and the chain should end at a process cause, not at blaming a person.

Example sentences

  1. We did a 5 Whys on the leak and found that the torque tool had not been calibrated since March.

  2. Don't stop the 5 Whys at 'operator error'; ask why the error was possible.

Common collocations

  • do a 5 Whys
  • 5 Whys analysis
  • 5 Whys template
  • ask why five times
  • root cause analysisA structured way of finding the deepest reason for a problem, so that it can be fixed for good instead of only treating the symptoms. Often shortened to RCA.
  • fishbone diagramA cause-and-effect diagram shaped like a fish skeleton: the problem is the head, and the bones list possible causes in groups such as people, machine, method, material, measurement and environment.
  • corrective actionAn action taken to remove the cause of a problem or nonconformance so that it does not happen again, not just to fix the affected parts.
  • poka-yokeA simple device or design feature that prevents a mistake or makes it obvious at once, such as a part that can only fit one way. Japanese for 'mistake-proofing'.

More terms: Process Improvement

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