Or ganization development is an effort (1) planned, (2) organization-wide, and (3) managed from the top, to (4) increase organization effectiveness and health through (5) planned interventions in the organization's "processes," using behavioral-science knowledge. 1. It is a planned change effort. An OD program involves a systematic diagnosis of the organiza-tion, the development of a strategic plan for improvement, and the mobilization of resources to carry out the effort. 2. It involves the total "system." An organization-development effort is related to a total organiza-tion change such as a change in the culture or the reward systems or the total managerial strategy. There may be tactical efforts which work with subparts of the organization but the "system" to be changed is a total, relatively autonomous organization. This is not necessarily a total corporation, or an entire government, but refers to a system which is relatively free to determine its own plans and future within very gen-eral constraints from the environment.