quality cycle / PDCA cycle

In education and training, iterative four-step problem-solving process typically used in business process improvement.

or

In education and training, cycle of four stages one has to go through to realise continuous improvement, as described by Deming:

• P (plan): project phase;
• D (do): execution phase;
• C (check): control phase;
• A (act): action, adaptation and correction phase.