the optimum number of subordinates a manager can supervise is referred to as the
Span of control The sum of these three types of interactions is the number of potential relationships of a supervisor. Graicunas showed with these formulas, that each additional subordinate increases the number of potential interactions significantly. It appears natural, that no organization can afford to maintain a control structure of a dimension being required for implementing a scalar chain under the unity of command condition. Therefore, other mechanisms had to be found for dealing with the dilemma of maintaining managerial control, while keeping cost and time at a reasonable level, thus making the span of control a critical figure for the organization. Consequently, for a long time, finding the optimum span of control has been a major challenge to organization design. As Mackenzie (1978, p 121) describes it: