Situational Leadership Theory, or the Situational Leadership Model, is a model created by Paul Hersey and Ken Blanchard, developed while working on Management of Organizational Behavior. The theory was first introduced in 1969 as "life cycle theory of leadership". During the mid-1970s, life cycle theory of leadership was renamed "Situational Leadership Theory." The Situational Leadership Model has two fundamental concepts: leadership style and the individual or group's performance readiness level, also referred to as maturity level or development level.