Section 36.2 - Fundamental principles underlying procedures(a) The following general principles underlie the procedures outlined in this part: (1) Separations are intended to apportion costs among categories or jurisdictions by actual use or by direct assignment.(2) Separations are made on the "actual use" basis, which gives consideration to relative occupancy and relative time measurements.(3) In the development of "actual use" measurements, measurements of use are (i) determined for telecommunications plant or for work performed by operating forces on a unit basis (e.g., conversation-minute-kilometers per message, weighted standard work seconds per call) in studies of traffic handled or work performed during a representative period for all traffic and(ii) applied to overall traffic volumes, i.e., 24-hour rather than busy-hour volumes.(b) Underlying the procedures included in this manual for the separation of plant costs is an over-all concept which may be described as follows: (1) Telecommunications plant, in general, is segregable into two broad classifications, namely, (i) interexchange plant, which is plant used primarily to furnish toll services, and(ii) exchange plant, which is plant used primarily to furnish local services.(2) Within the interexchange classification, there are three broad types of plant, i.e., operator systems, switching plant, and trunk transmission equipment. Within the exchange classification there are four board types of plant, i.e., operator systems, switching plant, truck equipment and subscriber plant. Subscriber plant comprises lines to the subscriber.(3) In general, the basis for apportioning telecommunications plant used jointly for state and interstate operations are:(i) Operator work time expressed in weighted standard work seconds is the basis for measuring the use of operator systems.(ii) Holding-time-minutes is the basis for measuring the use of local and toll switching plant.(iii) Conversation-minute-kilometers or conversation 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-kilometers is the basic fundamental allocation factor for interexchange circuit plant and exchange trunk plant, the use of conversation-minute-kilometers 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 state and interstate operations when related to the broad types of plant classifications used herein.(iv) Message telecommunications subscriber plant shall be apportioned on the basis of a Gross Allocator which assigns 25 percent to the interstate jurisdiction and 75 percent to the state jurisdiction.(c) Property rented to affiliates, if not substantial in amount, is included as used property of the owning company with the associated revenues and expenses treated consistently: Also such property rented from affiliates is not included with the used property of the company making the separations; the rent paid is included in its expenses. If substantial in amount, the following treatment is applied: (1) In the case of property rented to affiliates, the property and related expenses and rent revenues are excluded from the telephone operations of the owning company, and(2) In the case of property rented from affiliates, the property and related expenses are included with, and the rent expenses are excluded from, the telephone operations of the company making the separation.(d) Property rented to or from non-affiliates is usually to be included as used property of the owning company with the associated revenues and expenses treated consistently. In the event the amount is substantial, the property involved and the revenues and expenses associated therewith may be excluded from or included in the telecommunications operations of the company. When required, the cost of property rented to or from non-affiliates is determined using procedures that are consistent with the procedures for the allocation of costs among the operations.(e) Costs associated with services or plant billed to another company which have once been separated under procedures consistent with general principles set forth in this part, and are thus identifiable as entirely interstate or State in nature, shall be directly assigned to the appropriate operation and jurisdiction.52 FR 17229, May 6, 1987, as amended at 58 FR 44905, Aug. 25, 1993; 71 FR 65745 , Nov. 9, 2006