Shewart cycle

Four-step process used in quality control and elsewhere as a simplified method of achieving improvements. These steps are: (1) Plan: determine what needs to be done, when, how, and by whom. (2) Do: carry out the plan, on a small-scale first. (3) Check: analyze the results of carrying out the plan. (4) Act: take appropriate steps to close the gap between planned and actual results. Named after its proposer, the US mathematician Dr. Walter Shewart (1891-1967). Also called Deming cycle, Deming wheel, or plan do check act (PDCA) cycle.