How to Build an Inventory Management Solution That Prevents Stock Drift

说明与用途

该方案通过确保库存变更的原子性、幂等性和可审计性，防止库存漂移，降低超卖并改进补货决策。

问题

Warehouse dashboards often show more available stock than the picking team can find, leading to overselling, failed fulfilment, and incorrect replenishment decisions.

结果

The solution prevents stock drift by ensuring all inventory changes are atomic, idempotent, and auditable, reducing overselling and improving replenishment accuracy.

工作流

• Define separate tables for inventory_balance, inventory_reservation, inventory_movement, and processed_events.
• Use a composite key on (sku, warehouse_id) to avoid duplicate balance records.
• Implement a conditional UPDATE on inventory_balance that reserves stock only if sufficient unreserved quantity exists.
• Wrap the UPDATE, reservation creation, and movement recording in a single database transaction.
• Insert a record into processed_events with a unique constraint to deduplicate events.
• If the event is a duplicate, rollback and return a duplicate flag.
• If the conditional UPDATE fails, throw an error for insufficient stock.
• Commit the transaction on success.
• Separate external notifications from database commits to avoid race conditions.
• Retry failed downstream notifications via a background worker.

证据

A warehouse dashboard can show 120 units available while the picking team finds only 93.

来源

The following PostgreSQL statement performs a conditional reservation.

来源