# Inventory Accuracy Metrics That Reveal Real Problems

Canonical: https://millbase.ca/blog/inventory-accuracy-metrics-that-reveal-real-problems
Author: [Coby Birenbaum](https://www.linkedin.com/in/cobybirenbaum/)
Published: 2026-10-19
Updated: 2026-10-19
Archive edition: 2026-05-05

Inventory accuracy depends on what is being measured: item counts, location records, quantities, or value.

Inventory accuracy depends on what is being measured: item counts, location records, quantities, or value. Choose a definition that matches the decision and keep the counting method consistent. A single percentage can hide a serious shortage in a critical item.

## Define the metric

- State whether an accurate record means exact quantity or an approved tolerance.
- Track item-location accuracy separately from total item quantity where useful.
- Record the number and type of items counted so the sample is interpretable.
- Review critical shortages individually, even when the overall rate looks good.

## Worked example

If 46 of 50 counted item-location records match exactly, the illustrative exact-match rate is 92%. That does not mean 92% of inventory value is correct. A separate value-based measure would need quantities, costs, and a defined calculation.

## Use the result

Investigate trends by receiving, picking, returns, and transfers. Changing the tolerance to improve the headline number does not repair a process.

## Related reading

- [Inventory Management Software for Woodworking: What to Track First](https://millbase.ca/blog/inventory-management-software-for-woodworking-what-to-track-first)
- [Tracking Work in Progress Inventory in a Millwork Shop](https://millbase.ca/blog/tracking-work-in-progress-inventory-in-a-millwork-shop)

## Definitions and further reference

- [Oracle: inventory management explained](https://www.oracle.com/scm/inventory-management/what-is-inventory-management/)

## How Millbase can help your shop

### Connect material records to the cabinet job

When a component shortage or material change affects a job, start with the recorded stock and the work it supports. [Millbase inventory](https://millbase.ca/#inventory) keeps quantities, material costs, receipts, stock lots, and usage history together. Use [project tracking](https://millbase.ca/#projects) to review the associated labour and material costs, then reconcile the physical material before making a new commitment.

Ask the [Millbase AI agent](https://millbase.ca/#how-it-works) a question grounded in your workspace records. For example: *“What inventory records do we have for this material, and what usage is recorded against this project?”* You can select a project or worker, ask follow-up questions, and request [supported reports and CSV exports](https://millbase.ca/#insights).

Use the answer to locate the relevant records and investigate the exception. A physical count, approved specification, or supplier confirmation still establishes facts that have not been recorded.

## Explore the wider topic

For the broader workflow and decisions behind this guide, read [Warehouse Inventory Management for Project-Based Manufacturing](https://millbase.ca/blog/warehouse-inventory-management-for-project-based-manufacturing).

## Frequently asked questions

### Can two accuracy reports disagree legitimately?

Yes. They may use different samples, tolerances, units, or definitions. Compare the method before comparing the result.

### Should all items be weighted equally?

Equal weighting is useful for some process checks, but criticality and value deserve separate views. Avoid hiding one inside an unexplained blended score.