Duncan (1979) suggested that organizational structure is more than boxes on a chart. It is a pattern of interactions and co-ordination linking technology, tasks and human components of the organization to ensure the organization accomplishes its purpose. The tools used to add structure include: Organizational chart - a diagram of formal relations which the company intends should prevail within it. Job definitions - the task requirements of a particular job in the organization. Span of control - the number of subordinates who report directly to a single manager or supervisor. The principle of span of control states that administrative efficiency is increased by limiting the span of control of a leader to no more than five or six subordinates whose work interlocks. Authority - the right to guide or direct the actions of others. Responsibility - an obligation placed on a person, who occupies a certain position in the organization structure, to perform a task, function or assignment. Accountability - responsibility for some activity. When establishing the structure, designers typically start by defining larger groups and then decompose them into smaller units. Departmentalization is a process of grouping together employees who share a common supervisor and resources, who are jointly responsible for performance and who tend to identify and collaborate with each other. The organizational chart usually shows the departments within an organization. The chart also shows relationships between departmental staff in the organization which can be Line (direct relationship between superior and subordinate); Lateral (relationship between different departments on the same hierarchical level), Staff and functional. At a high level, designers distinguish between different categories of employee. For example Staff employees are workers who are in advisory positions and who use their specialized expertise to support the efforts of line employees. Employees may be related to one another in a variety of ways. A Line relationship is a formal relationship between individual positions within an organisation where authority flows vertically down through the structure; a Functional relationship is where staff department specialists have the authority to insist that line managers implement their instructions concerning a particular issue and Lateral relationships are formal relationships which exist between individuals in different departments or sections, especially between individuals on the same level. In many large companies the organization chart can be large and incredibly complicated and is therefore sometimes broken down into smaller charts for each individual department within the organization. There are several limitations with organizational charts. Firstly, they only show 'formal relationships'. Secondly they do not show anything about the managerial style adopted (e.g. Autocratic or democratic).