Network models provide a natural form for expressing a broad range of problems.
The range of applications that have evolved since that time testifies to the continued validity of this observation. The pictorial nature of network models enhances communication and increases their acceptance by potential users. Managers and decision makers are naturally reticent to commit their budgets to mathematical models that they do not understand. A background in operations research is not prerequisite to appreciating analogies to actual problems. As a result, such accessibility has led to strong acceptance of the network formulation.