First In, First Out: Implement FIFO for efficient stock rotation, optimize inventory flow, reduce costs, and minimize obsolescence risks. What is the full form of FIFO ? - First In, First Out - FIFO is an acronym that stands for First In, First Out. In a FIFO system, the first item placed into FIFO — First In, First Out. It is a method of accounting and inventory management where the oldest stock or items go first, before the newer ones. This is particularly advantageous for sectors working with perishable and time-bound products, for example, food, medications, and retail. FIFO , FEFO and LIFO are the three main strategies for warehouse management. But what do the three abbreviations actually stand for and what exactly do they mean?