Organization Development (OD) is defined as a systematic process that applies behavioral science principles to help organizations change and improve. It emerged in the late 1940s from the fields of group dynamics and planned change theory. OD focuses on long-term, organization-wide efforts led from the top to increase effectiveness through interventions in organizational processes. Major themes of OD include planned change, a distinctive self-renewal approach, a total systems perspective, and action research. Over time, OD has been influenced by different approaches like laboratory training, action research, participative management, quality of work life programs, and a growing focus on strategic change.