Mintzberg argues that making decisions is the most crucial part of any managerial activity. He identifies four roles which are based on different types of decisions; namely, entrepreneur, disturbance handler, resource allocator and negotiator.

As entrepreneurs, managers make decisions about changing what is happening in an organisation. They may have to initiate change and take an active part in deciding exactly what is done – they are proactive. This is very different from their role as disturbance handlers, which requires them to make decisions arising from events that are beyond their control and which are unpredictable. The ability to react to events as well as to plan activities is an important aspect of management. The resource allocation role of a manager is central to much organisational analysis. A manager has to make decisions about the allocation of money, equipment, people, time and other resources. In so doing a manager is actually scheduling time, programming work and authorising actions. The negotiation role is important as a manager has to negotiate with others and in the process be able to make decisions about the commitment of organisational resources.

Mintzberg found that managers don’t perform equally – or with equal frequency – all the roles he described. There may be a dominant role that will vary from job to job, and from time to time.

It is important to note that many non-managers in organisations seem to have these sorts of interpersonal, informational and decisional roles. For example, a hotel receptionist is fulfilling an interpersonal role when she meets the hotel guests’ needs by communicating with the room attendants and restaurant staff. A car park attendant who monitors how full the car park is and, when necessary, displays the sign ‘car park full’ is disseminating information. When the same attendant sends the larger cars to the areas of the car park where there is more space, he is acting as a resource allocator. But in each case routine situations are being handled in routine ways. In contrast, the situations managers deal with differ in the degree of routine, the size and scope and complexity of the activities in which they are involved, and the responsibilities associated with these activities.