When the number of items of same type of industrial property is quite large, calculating depreciation for a group of such item may be more efficient than depreciating each item separately. Also, predicting the service life of a specific individual unit is very difficult to do with any degree of accuracy. Estimating the probable average service life (PASL) of many units (or dollars) is not an easy task; however, an average life of many units can probably be predicted with a much higher degree of accuracy than the life of some particular unit. Using the average of many units allows for some units having relatively short lives and some units having relatively long lives without specifying whether a particular unit will have a short or a long life. If the life of each vintage in an account are not estimated, then the broad group procedure can be used. The broad group procedure depreciates the several vintage in an account as a single group. The PASL for this procedure is the estimate of the average of lives of the individual dollars in the group. If the estimated PASL’s of the vintages are not the same, then a weighted average PASL would have to be calculated for each calendar year. In this paper, we illustrate the calculations of accrual rates and the annual depreciation charge for each of the calendar years by the broad group depreciation procedure.