20:10:28:06Apportionment of telecommunications plant -- General.

In general, the bases for apportioning telecommunications plant used jointly for toll and other services are as follows: (1) Operator work time expressed in weighted standard work seconds is the basis for measuring the use of operator systems; (2) Holding-time-minutes is the basis for measuring the use of switching plant; (3) Conversation-minute miles or conservation-minutes is the basis for measuring the use of interexchange circuit plant and holding-time minutes is the basis for measuring the use of exchange trunk plant. While the use of holding-time-minute-miles is the basic fundamental allocation factor for interexchange circuit plant and exchange trunk plant, the use of conversation-minute-miles or conversation-minutes for the allocation of interexchange circuit plant and holding-time minutes for the allocation of exchange trunk plant are considered practical approximations for separations between toll and other services when related to the broad types of plant classifications used in this chapter; (4) A subscriber plant factor is the basis of apportioning the cost of message telecommunications subscriber plant and local switching plant between intrastate and interstate operations. The subscriber plant factor is developed and used according to the procedures set forth in § 20:10:28:61.

Source: 19 SDR 111, effective January 31, 1993.