Kyle Moloney
Procurement & Operations | 10+ Years
Kyle has spent over a decade managing procurement and operations for manufacturing companies ranging from small food producers to mid-size contract manufacturers. He now writes about practical inventory management, supply chain, and production operations.
A total inventory value tells you how much money is tied up on your shelves right now. It doesn't tell you whether that money has been sitting there for a week or for four months. The Inventory Aging Report answers the second question — and it's usually the more urgent one.
How It's Calculated
As of today, Nstock groups every on-hand raw material lot and finished goods lot into one of four age buckets, based on how long ago the lot was purchased or last received:
- 0–30 days
- 31–60 days
- 61–90 days
- 90+ days
For each lot, age is calculated from its purchase date (or last-received date, if that's what's available) to today. Lot value is quantity on hand multiplied by unit cost — the same cost basis (order price plus shipping) used elsewhere in Nstock's valuation reports. Those values are summed into two separate tables, one for raw materials and one for finished goods, each broken out across the four buckets, with the 90+ day column called out visually since that's where the real risk concentrates. Lots with no recorded purchase or last-received date are excluded from the totals and flagged separately, since there's no reliable date to age them from.
Why a Finance or Ops Person Would Check It
Total valuation and aging tell different stories, and you need both. A Monthly Inventory Report showing a stable total value can be hiding a bucket of 90+ day stock that's quietly growing behind a bucket of fresh stock that's shrinking — the total looks fine while the composition gets worse. Ops teams use aging to decide what to push through production or promotions before it becomes dead stock; finance teams use it to flag working capital that isn't going to convert back to cash on any predictable schedule, and to get ahead of a write-off conversation instead of being surprised by one at year-end. If aging turns out to be concentrated in one brand or one location, Finance Reports by Brand and Warehouse can help narrow down exactly where before you decide what to do about it.
Watch for This
A 90+ day raw materials bucket that keeps growing month over month, even while total inventory value looks flat, usually means a purchasing habit is outrunning a production or formulation change — you're still buying a material on the old schedule after usage dropped, a supplier minimum order quantity forces you to buy more than you consume, or a SKU got discontinued without anyone updating the purchasing pattern. Left alone, that bucket doesn't just sit there quietly: it becomes tomorrow's write-off, and if it's a component with shelf life or expiry, its usable window can close before anyone reallocates it. The earlier it's caught, the more options exist — rework it into a different product, sell it off, or negotiate a return — versus a straight loss once it expires or goes obsolete.
Frequently Asked Questions
Why are raw materials and finished goods shown separately?
They carry different risk profiles and usually need different responses. Aging raw materials is often a purchasing or formulation problem; aging finished goods is often a sales or demand-forecasting problem. Blending them into one number would hide which lever actually needs pulling.
What if a lot has no purchase date?
It's excluded from the aging totals and called out separately with a count, rather than silently defaulting to a bucket that might misrepresent it. If you're seeing excluded lots, check that receiving is consistently recording a purchase or received date.
Does this account for whether a lot has partially sold or been consumed?
Age reflects how long the lot has been on hand, not whether any of it has moved. A large 90+ day value is worth investigating even if some of that lot has since been used — it means what's left has been sitting even longer than the lot's original receipt date might suggest at a glance.
How does this relate to FEFO?
Aging and first-expired-first-out lot selection are related but not identical — FEFO prioritizes lots by expiry date when fulfilling orders, while aging is based on how long a lot has been on hand. A lot can be aging heavily in dollar terms without being close to its expiry date, or vice versa.
Next Steps
Aging pairs naturally with Inventory Turnover — a falling turnover ratio and a growing 90+ day bucket are often the same underlying problem seen from two angles. For the total valuation this report breaks down by age, see Monthly Inventory Report Explained. And if a chunk of your aging raw materials is tied up because production hasn't consumed it yet, check whether it's already been issued to a batch — see WIP Valuation Explained and Open Purchase Commitments for what's coming in behind it.
Start your free trial → — already have an account? Log in and find Inventory Aging under Reports → Finance.
— Kyle Moloney, Procurement & Operations