Every facility maintenance team eventually asks the same question: are we spending too much on spare parts, or not enough? The answer isn't guesswork — it lives inside four measurable numbers that reliability professionals track year over year: inventory turnover, carrying cost, dead stock ratio, and inventory value as a percentage of replacement asset value. Most facilities discover, once they actually run these numbers, that fifteen to twenty five percent of their MRO inventory hasn't moved in over a year while critical spares still run short at the worst possible moment. Turning those four numbers into a live, trackable score is exactly what OxMaint's CMMS platform helps facility teams do.
Your Storeroom Has a Number. Most Facility Teams Have Never Seen It.
Inventory turnover, carrying cost, dead stock, and stock-to-RAV ratio are the four numbers reliability engineers use to grade a storeroom. Run them against your own parts data and see exactly where your facility falls before the next audit or budget review does it for you.
The Four Numbers That Grade Every MRO Storeroom
Turnover Isn't One Number — It's Three, by Category
Applying a single turnover target to an entire storeroom is where most benchmarking goes wrong. A bearing that fails once a decade should barely move, while a filter that gets replaced every month should turn over constantly — grading them against the same number hides both problems.
What Each Benchmark Is Actually Telling You
| Benchmark | Healthy Range | What a Bad Number Means | Fix |
|---|---|---|---|
| Inventory Turnover | 1.0x - 3.0x general spares | Too low signals dead capital; too high on critical parts signals repeated failures | Split min/max by criticality class, not one storeroom-wide rule |
| Carrying Cost | 20% - 30% of value / year | Every dollar sitting idle costs another 20-30 cents just to keep it on the shelf | Right-size reorder points against real lead-time demand |
| Dead Stock Ratio | Under 10% of catalog value | Parts tied to retired assets or with zero issues in 24 months are pure loss | Run a monthly zero-issue scan and route hits to redeploy or scrap |
| Stock as % of RAV | Under 1.5% at maturity | A high ratio means the storeroom is growing faster than the assets it protects | Benchmark every purchase against replacement asset value, not habit |
OxMaint pulls turnover, carrying cost, dead stock, and RAV ratio straight from your issued work orders and purchase history, then keeps every SKU classified by criticality so the right benchmark applies to the right part.
From Spreadsheet Guesswork to a Live Benchmark Score
The number I care about most isn't the average turnover ratio — it's how many SKUs in the catalog nobody can explain. If a planner can't tell me why a part is on the shelf or what asset it belongs to, that part is costing the plant money whether it ever fails or not. Benchmarking only works once every part has an owner, a criticality class, and a reason to exist in the storeroom.
Frequently Asked Questions
What is a good MRO inventory turnover ratio for a facility?
Most facility storerooms should land between 1.0 and 3.0 turns a year for general spares. Critical, low-failure parts can sit well under 0.5 without being a problem, while consumables like filters and belts often turn 3 to 4 times a year.
How is MRO carrying cost calculated?
Carrying cost is usually expressed as a percentage of average inventory value, typically 20 to 30 percent annually once storage space, insurance, taxes, and obsolescence risk are included. Start a free trial to see this calculated against your own catalog.
How much dead stock is normal in a spare parts storeroom?
Industry data consistently points to 15 to 25 percent of MRO inventory value sitting idle, tied to retired equipment or parts with no issues recorded in the past year or two.
Can OxMaint track these benchmarks automatically?
Yes. OxMaint calculates turnover, carrying cost, dead stock ratio, and stock-to-RAV directly from work order and purchasing history, refreshed as parts move. Book a demo to see it against your live data.
What does stocked inventory as a percent of RAV mean?
It compares the dollar value of parts on the shelf to the replacement value of the assets they support. Mature, top-quartile facilities generally keep this figure under 1.5 percent.
Stop Guessing What Your Storeroom Costs You
OxMaint turns turnover, carrying cost, dead stock, and RAV ratio into one live dashboard tied to your actual assets and work orders, so every part on the shelf has a reason to be there.
