Eric Ries explains Taiichi Ohno’s “Five Whys” and its application for process improvement in the software industry.

Executive summary

  • When a problem occurs, it can be broken down to errors at various levels.
  • We clearly and concisely formalise five of these and attach a positive corrective action to the process for each.
  • We assign a ‘proportional investment’ to each of the corrective actions, being careful not to over-allocate resources in a reactionary way.
  • Propose the corrective actions to the whole team and respond to their reactions.
  • Over time, corrective actions become incorporated – gradually improving flow.
  • This focusses on process enhancement, and attempts to mute any technical bias.
  • Reoccurring (80-20) problems will pass through multiple times, causing incremental but proportionate refinement, and will eventually be weeded out.