A method of inventory bookkeeping where the book (computer) inventory of components is automatically reduced by the computer after completion of activity on the component’s upper-level parent item based on what should have been used as specified on the bill of material and allocation records. This approach has the disadvantage of a built- in differential between the book record and what is physically in stock. Synonym: explode-to- deduct. Also see: Pre-deduct Inventory Transaction Processing.