8dd8e1b3_O_Accounting___AccountingTools__LIFO_Method
[Issue] Reporting fluctuations [FIFO Method] Since there are few inventory layers, and those layers reflect recent pricing, there are rarely any unusual spikes or drops in the cost of goods sold that are caused by accessing old inventory layers. [LIFO Method] 
There may be many inventory layers, some with costs from a number of years ago. If one of these layers is accessed, it can result in a dramatic increase or decrease in the reported amount of cost of goods sold.
FIFO vs LIFO Accounting - AccountingTools
LIFO Method