Effects of Scanning Interval on Peak Load Measurements

The determination of the load carried by a group of circuits is of prime importance in facilities engineering. The present technique for acquiring data is the switch count method. Here the equipment is scanned at fixed intervals, and the total number of busy circuits is recorded. Dividing this total by the number of scans during the observation interval yields an estimate of the carried load in erlangs. Typically, a day may contain N such observation intervals. The daily bouncing busy-hour measurement is obtained by retaining the largest usage measurement of the N daily observation intervals. Averaging this quantity over a number of days should give an indication of average peak loads to be expected. Since there is some inherent error between the carried load of an observation interval and that determined by the switch count method, it is important to know the effect of this discrepancy on the expected bouncing busy-hour measurement.