Critical Section Methods for Loop Plant Allocation

The purpose of allocation in the loop plant network is to use existing and future facilities efficiently to reduce the cost of providing customer service and to defer expanding the capacity of the network (with new feeder facilities). Allocation procedures for the loop plant network were originally described by Marsh.' These procedures were developed specifically for feeder routes experiencing significant annual customer growth. The objective was to improve the utilization of existing facilities to defer placing new cable facilities. This is accomplished by apportioning space feeder pairs along a route in proportion to forecasted growth rates. Not all routes, however, have high growth, Many, particularly in large urban centers, are characterized by considerable customer movement with little or no net growth. Customers move from one location to another with no effect on total demand. On routes of this type, the costs associated with inward and outward movement predominate. Models of network operating costs associated with customer movement 99