Span of Control

The span of control principle suggests that there is a limit to the number of persons one manager can effectively supervise, and care should be taken to keep the span of control within manageable limits. Some authors prefer the term 'Span of Management' to span of control, since, from a system viewpoint, managers have many more activities than simply controlling subordinates. 

Essentially, as the numbers of subordinates increases arithmetically, the number of relationships between the manager and the subordinates increases geometrically. The number of relationships, r is calculated by using the following formula : 

r=n(2^n-1 + n-1) 

where n represents the number of subordinates. 

For example, if  a manager has four subordinates, the theoretical numbers of relationships between the manager and the subordinates is 44. The addition of a fifth subordinate results in 100 potential relationships and eight subordinates mean 1,080 potential relationship. 

The number of organisational levels depends on the span of control. An organisation that has a small number of subordinates reporting to each manager generally has many levels of management and is thus considered "tall". On the other hand, an organisation that has a large number of subordinates reporting to each manager has few levels and is thus considered "flat". 

Factors Influencing Span of Control 

The proper number of subordinates for each manager ultimately depend on the individual manager, the subordinates, the type of work, and other considerations listed below : 

• the competence of both the superior and the subordinates 
• The degree of interaction between the units or personnel being supervised. 
• The extent to which the supervisor must carry out non-managerial responsibilities and the demands on his time from other people and units. 
• The similarity or dissimilarity of the activities being supervised. 
• The incidence of new problems in his unit. 
• The extent of standardised procedure. 
• The degree of physical dispersion. 

From this it follows that some managers are more capable that others of supervising large members of people. The more simple, routine, and repetitive the work, the greater the possible span of control. The more interdependent the units, the greater the need for coordination and the smaller the optimal span of control. The more efficient the organisation and the greater competence of its employees, the larger the span of control.