Keep in mind that fifo is applied within each department to compile the cost of units transferred out. As a practical matter, however ,unit transferred in during a given period usually are carried at a single average unit cost .for example, in the preceding example, the assembly department uses FIFO to distinguish between monthly batches of production. The resulting average cost of each SG-40 unit transferred out of the assembly department is $ 52,480 / 400 units=$131.20. the testing department ,however ,costs these unit (which consist of costs incurred in both February and march ) at one average unit cost ($131.20 in the example). If this average were not done ,the attempt to track costs on a pure FIFO basis throughout a series of processes would be cumbersome .As a result ,the FIFO method should really be called a modified or department FIFO method