The work planning process structure evolved from research, discussion, and review by means of a successive series of "Plan, Do, Study, Act" (PDSA) cycles. The structure is based on the concepts of manager as mentor and the achievement of "mastery" levels by individual staff members. It emphasizes the fact that staff clearly have a crucial understanding of the work that needs to be done, and how their individual or group effort contributes to the system. The process is structured so that it is adaptable to both individual and group work planning situations.