Bufferinventar

Bufferinventar, or buffer inventory, is inventory kept at strategic points within a production process or supply chain to absorb variability in demand and lead times. Its main purpose is to decouple operations, ensuring continuity of production and on-time delivery despite fluctuations. Buffer inventory is typically placed between processes or at entries to suppliers or factories, acting as decoupling stock that shields downstream operations from upstream variability. It is often distinguished from regular cycle stock, which covers expected demand, and from the broader safety stock concept, serving as protection against unexpected changes at a particular point in the chain.

Calculation and management of buffer inventory involve estimating service level targets, historical demand and lead-time variability, and the required responsiveness. Methods range from simple safety-stock formulas to more advanced probabilistic models; some systems implement fixed buffer sizes as part of Kanban or other pull-based methods. The goal is to set a size that balances the risk of stockouts against carrying costs and capital tied up in inventory.

Benefits of buffer inventory include reduced risk of production stoppages, smoother planning, and improved throughput. Drawbacks include higher carrying costs, potential obsolescence if demand shifts, and the need for regular review and adjustment to stay aligned with the overall inventory strategy.

Examples include placing buffers between subassembly and final assembly lines, or between suppliers and manufacturing sites to cover supplier delays. In practice, buffer inventory is a common tool in manufacturing and logistics to manage variability and maintain service levels. See also safety stock, decoupling stock, Kanban, lead time, and service level.