Originally Shewhart’s Plan-Do-Check-Act or the application of the scientific method to engineering and management. Deming later changed Check to Study. A look-before-you-leap approach to standardization or maintenance (Standardize-Do-Check-Act), solving problems and improvement or reactive mode (Check-Act-Plan-Do) and achieving opportunities and new developments or proactive mode (Plan-Do-Check-Act).
PDCA (aka the Shewhart Cycle or the Deming Wheel) is an iterative four-step quality control strategy.
PLAN – establish the objectives and processes necessary to deliver results in accordance with the specifications.
DO – implement the processes.
CHECK – monitor and evaluate the processes and results against objectives and Specifications and report the outcome.
ACT – apply actions to the outcome for necessary improvement.
(From Wikipedia, the free encyclopedia).