Application of Sequencing Policies to Telephone Switching Facilities

Sequencing policies for telephone switching facilities are examined. During the transient period, when old switching facilities are being replaced by new ones, substantial costs are incurred to guarantee uninterrupted service to all customers. These costs depend on the sequence chosen for transferring trunk groups from the old facility to the new one. A dynamic programming model is formulated to determine the optimal sequence. To facilitate the computation for problems of realistic size, a bounding procedure is developed which considerably reduces the storage requirements without sacrificing optimality. Thereafter, a heuristic is developed for larger facilities with up to about fifty trunk groups. The model has been computerized and is currently being used. Numerical examples and applications are discussed.