key takeaways
If you only read 30 seconds of this article:
- You can safely cut non-moving excess, duplicates, and overstock on rarely-failing parts; you cannot cut critical, long-lead, or intermittent line-stop parts.
- The safe cuts are large: industry studies suggest 50 to 60% of MRO inventory is excess, obsolete, or slow-moving.
- Sequence matters: fix the data and pool stock first, then cut tier by tier, holding the critical few.
- Cutting before the data is trustworthy is what creates stockouts; a major US energy company verified $29.7M by reducing on unified, criticality-scored data, based on Verusen customer results.
Spare parts inventory reduction
Short answer: You can safely reduce spare parts inventory by removing non-moving excess, duplicate parts, and overstock on parts that rarely fail, and you cannot safely cut critical, long-lead, or intermittent line-stop parts, whose failure stops production. The safe cuts are large, because industry studies suggest 50 to 60% of MRO inventory is excess, obsolete, or slow-moving. The rule that keeps reduction safe is to fix the data and stock to criticality first, then cut tier by tier, holding the critical few.
Spare parts inventory reduction: Lowering total spare-parts inventory by removing excess, obsolete, and duplicate stock while protecting the critical parts whose failure would halt production.
What you can cut safely, and what you can't
The line between a safe cut and a risky one is criticality. Non-moving excess, duplicate parts, and overstock on low-consequence items are cash sitting idle; cutting them carries no production risk. Critical, long-lead, and intermittent line-stop parts are the opposite: their carrying cost is trivial next to the downtime their absence causes, so cutting them to hit a number is how reduction programs cause the outages they were meant to avoid. Purpose-built MRO inventory optimization draws this line automatically by scoring every part.
| Cut safely | Never cut |
|---|---|
| Non-moving stock (24+ months no use) | Critical line-stop parts |
| Duplicate parts across sites | Long-lead insurance spares |
| Overstock on rarely-failing items | Intermittent high-consequence parts |
| Obsolete parts for retired assets | Regulated or single-source parts |
The classification that separates the two columns is the criticality method in MRO criticality analysis; this guide to reducing excess and obsolete inventory is a useful companion.
Spare parts inventory reduction safe vs risk
How big the safe cuts are
The safe cuts are not marginal. Industry studies suggest 50 to 60% of MRO inventory is excess, obsolete, or slow-moving, and 30 to 50% of parts have not moved in 24 months. That is the pool you can release without touching a single critical part, which is why the right reduction program lowers the total substantially while availability holds or improves. This MRO spares optimization guide and this spare parts inventory management guide corroborate the scale.
| MRO inventory that is excess, obsolete, or slow-moving (industry studies) | 50-60% |
| parts not moved in 24 months (industry studies) | 30-50% |
| energy company: verified on unified, scored data | $29.7M |
Spare parts inventory reduction results
The sequence that keeps reduction safe
Reduction goes wrong when it starts with the levels instead of the data. The safe sequence fixes visibility first, so every cut is made against the truth.
- Unify and de-duplicate materials across every ERP so on-hand and criticality are true.
- Score every part by criticality and lead time before cutting anything.
- Release non-moving excess and obsolete stock first, the safest, largest pool.
- Trim overstock on low-consequence parts against real consumption.
- Hold or increase critical and long-lead buffers; the savings fund the protection.
A major US energy company reduced on exactly this basis, reviewing 45,000 materials on unified, criticality-scored data and verifying $29.7M while achieving 100% audit capability, based on Verusen customer results. Most customers reach a working solution in under 45 days and unlock $20M in working capital on average, no cleanse first. Then talk to an MRO expert to see what you can cut safely.
Further reading: reducing excess and obsolete inventory, MRO spares inventory optimization guide, and spare parts inventory management guide.
Frequently asked questions
Non-moving stock that has not been used in 24+ months, duplicate parts across sites, overstock on rarely-failing items, and obsolete parts for retired assets. These are cash sitting idle, and cutting them carries no production risk.
Critical line-stop parts, long-lead insurance spares, intermittent high-consequence parts, and regulated or single-source parts. Their carrying cost is trivial next to the downtime their absence causes, so cutting them to hit a number causes outages.
A lot: industry studies suggest 50 to 60% of MRO inventory is excess, obsolete, or slow-moving, and 30 to 50% of parts have not moved in 24 months. That pool can be released without touching a single critical part.
Because they start with the levels instead of the data, cutting to hit a number before knowing which parts are critical. Cutting before on-hand and criticality are trustworthy removes the wrong stock and creates the outages the program was meant to avoid.
Unify and de-duplicate materials first, score every part by criticality, release non-moving excess and obsolete stock, trim low-consequence overstock, and hold critical buffers. A US energy company verified $29.7M reducing this way, based on Verusen customer results.
PN
- Paul Noble
- CRO, Verusen
Chief Revenue Officer (CRO) at Verusen AI – AI Built for Industry. Designed to Solve What Legacy Systems Can’t.