Leadership and management are two distinctive and complementary systems in action. Each has its own function and characteristic activities and both are essential.
However, management is about coping with complexity and leadership is about coping with change. While most companies tend to be over managed and underled, the reverse (overled and undermanaged is not necessarily better either). Consider a simple military analogy: A peacetime army can usually survive with good management up and down the hierarchy with some really good leadership at the top. However, a wartime army require competent leadership at all levels. No one yet has figured out how to manage people effectively into a battle; they must be led.
These different functions - coping with complexity vs coping with change - shape the characteristic activities of management and leadership. Each system of action involves what needs to be done, creating networks of people and relationships that can accomplish an agenda, and then trying to ensure that those people actually do the job. But each accomplishes these three tasks in different ways.
1. Companies manage complexity by planning and budgeting and establishing detailed steps to achieve those and allocating resources to accomplish these plans. By contrast leading an organization to constructive change begins first by setting a direction - developing a vision and strategies to accomplish that vision.
2. Management develops the capacity to achieve its plan by organising and staffing and devising systems to monitor implementation. The equivalent leadership activity is aligning people - communicating the direction and getting commitment.
3. Finally, management ensures plan accomplishment by controlling and problem solving - monitoring results vs plan by means of reports, meetings etc., and then planning and organising to solve the problems. But for leadership, achieving a vision requires motivating and inspiring, by appealing to basic but often untapped human needs, values and emotions.
Excerpts from HBR article What Leaders Really Do - John Kotter.