Strategic management in a corporation appears to evolve through four sequential phases according to Gluck, Kaufman and Walleck. Beginning with basic financial planning, it develops into forecast-based planning, and then into externally-oriented planning, and finally into a full-blown strategic management system. The evolution is most likely caused by increasing change and complexity in the corporation's external environment. The phases are thus likely to be characterized by a change from primarily an inward-looking orientation in the first phase to primarily an outward-looking orientation in the third phase, and to a more integrative orientation in the final strategic management phase with equal emphasis on both the external and internal environments.