Vertical structure—hierarchy and intervention
Having outlined the principles by which a horizontal structure for organisations may be decided upon, we now turn to the vertical structure.
The vertical structure of a social system is often hierarchical, with each level setting the limits of discretion for the next level down. In our terms, that discretion is the tertiary component of the work expected of that department, and the function of the exercise of that discretion is to ensure that the result handed up to the superior level of the hierarchy is acceptable. If the discretion is exercised satisfactorily, then it is not necessary for the superior level to intervene in the lower level.
The proportion of time that the superior level has to spend in intervening in the affairs of the lower level is what we call the intervention ratio
There is obviously a limit to the proportion of time that can be spent in intervening. For example, in a company, a manager cannot spend more than all the time intervening in the work of his subordinates.
It follows that, if subordinate units of a hierarchy require more time to be spent in intervention, then fewer of them can form that layer of the hierarchy. The classical principle of the dean, or decanus, is for a superior to be in charge of a group of ten subordinates. But these days, although the title still survives, the number of subordinates will depend on the degree of intervention they require.
The Law of Sum of Intervention Ratios
The basic principle, that the sum of the intervention ratios must not exceed unity, governs all hierarchical command structures.
Function of the top level
Incidentally, while we are discussing the vertical structure of these systems, it is worth making the point that, in a business or similar enterprise, the Board, or top level, has a different function from those below. Departments at lower levels work best if they are each dealing with, and specialising in, only one dimension of imparity. But the Board meets to bring together the highest level of each tertiary dimension, as required in the whole system.