Your inventory is not a safety net.
Extra stock feels like protection. Usually it protects the wrong SKUs, in the wrong place, at the wrong time.
After three years of disruption, many operations teams did the rational thing: they added inventory. Buffers went up across the board. Service improved, at first.
The problem is that a buffer applied everywhere is a buffer that isn't targeted anywhere. The SKUs with the most volatile demand and the least reliable suppliers get the same extra weeks as the SKUs that were never at risk.
The three failure modes of blanket buffers
- Excess on stable items. Predictable SKUs with reliable suppliers now carry weeks of stock they will never need.
- Shortage on volatile items. Extra weeks based on average demand still miss the peaks on high-variability items.
- Wrong location. In a multi-site network, total inventory can be high while the one DC that needs it is short.
Inventory is a position, not a policy. Every unit is a bet on where demand will show up.
Targeted buffers
Safety stock should scale with two things: how much demand varies and how much lead time varies. Both can be measured from your own ERP history. Once they are, most companies discover they can hold less stock in total and still protect service better on the items that matter.
What to do
- Segment SKUs by demand variability and supplier reliability.
- Recalculate safety stock from measured variability, not rules of thumb.
- Review cover by location, not just in total.
WERISCO shows parts below reorder point, shortest cover first, and the value held above your own target levels, item by item, from the exports you already run.
One supply-chain shock, decoded in numbers, and what a data-driven plant does about it.
