plan-do-check-action (PDCA)

Sometimes referred to as the Shewhart Cycle, for the inventor - Walter A. Shewhart. A four step process for quality improvement:
Plan - A plan to effect improvement is developed. Do - The plan is carried out, first, on a small scale if possible.
Check - The effects of the plan are observed. Action - The results are studied and observed to determine what was learned and what can be predicted.