Characteristic of our times are the concepts of complexity, growth and change. - Harold Chestnut

Formulating and structuring a system provide methods for relating (1) what the system consists of in the mind of the persons or group desiring it; (2)what it means in terms of the persons or group designing and building it; and (3) in terms of the persons or groups operating, using and servicing it. They provide a set of "reasonable" parts and methods of relating them so that the many persons working on the system can understand the whole in sufficient detail for their purposes, and their particular parts in explicit detail so that they may contribute their best efforts to the extent required. A further purpose of system formulation is to recognize the magnitude of the job, including the possible pitfalls.

Knowledge about the process being modeled starts fairly low, then increases as understanding is obtained and tapers off to a high value at the end.

In addition to technical problems, systems also have organizational and logistical problems. Many different people may be involved over a wide physical or geographic coverage and over a long period of time. Many may work for different companies or organizations with different rules and methods of operating. Very many data and much knowledge are involved. The organizational problem concerns itself with the question of how all these people can work together most effectively for the common purpose.