Table 1

Description of the plan–do–study–act (PDSA) cycle method according to developers and commentators

	Deming (1986)25Original description of the method relating to manufacturing	Langley (1996)30How the PDSA method may be adapted for use in healthcare contexts	Speroff and O'Connor (2004)33How the PDSA method is analogous to scientific methodology
Plan	Plan a change or test aimed at improvement	Identify objective Identify questions and predictions Plan to carry out the cycle (who, when, where, when)	Formation of a hypothesis for improvement
Do	Carry out the change or test (preferably on a small scale)	Execute the plan Document problems and unexpected observations Begin data analysis	Conduct study protocol with collection of data
Study	Examine the results. What did we learn? What went wrong?	Complete the data analysis Compare data to predictions Summarise what was learnt	Analysis and interpretation of the results
Act	Adopt the change, abandon it or run through cycle again	What changes are to be made? What will the next cycle entail?	Iteration for what to do next