At least with the addition of “Observe” and “hypothesize steps, the standard PDCA/PDSA Deming/Shewart cycle maps on to the experimental method as follows:

  • (Observe): Grasp the current problem situation.
  • (Hypothesize): Generate falsifiable hypothesis intended to improve situation. “A hospital might hypothesize that having doctors remove their neckties will reduce infections.”
  • Plan: Develop experimental design. “From April 1 to 30, doctors will not wear ties at work.”
  • Do: Execute experimental design. “Doctors come to work without ties from April 1 to 30.
  • Check/Study: Analyze results of experiment. “Compare hospital infection rate during this period with the previous months and check for improvement.”
  • Act/Adjust: If the hypothesis is falsified, begin cycle again, otherwise implement experimental design as standard work. “If infection rates drop, then continue the policy; if they stay the same, reject or modify the hypothesis and formulate another one.”
Example taken from A Factory of One, Daniel Markovitz, p.119.