In business and accounting/accountancy, perpetual inventory or continuous inventory describes systems of inventory where information on inventory quantity and availability is updated on a continuous basis as a function of doing business. Generally this is accomplished by connecting the inventory system with order entry and in retail the point of sale system. In this case, book inventory would be exactly the same as, or almost the same, as the real inventory.
In earlier periods, non-continuous, or periodic inventory systems were more prevalent. Starting in the 1970s digital computers made possible the ability to implement a perpetual inventory system. This has been facilitated by bar coding and lately radio frequency identification (RFID) labeling which allows computer systems to quickly read and process inventory information as part of transaction processing.
Perpetual inventory systems can still be vulnerable to errors due to overstatements (phantom inventory) or understatements (missing inventory) that can occur as a result of theft, breakage, scanning errors or untracked inventory movements, leading to systematic errors in replenishment.
Famous quotes containing the word perpetual:
“The human body is not a thing or substance, given, but a continuous creation. The human body is an energy system ... which is never a complete structure; never static; is in perpetual inner self-construction and self-destruction; we destroy in order to make it new.”
—Norman O. Brown (b. 1913)