Choose a boundary for the total
A material can appear in mine output, an intermediate shipment, separated product and downstream manufacturing statistics. Those observations are useful, but they may describe successive forms of the same material. Decide whether the analysis measures mined content, separated oxide, metal or finished magnets before aggregating quantities.
The stages described in the IEA's rare-earth value-chain analysis make this boundary important: transformations add industrial capability, not necessarily an additional independent source of feedstock.
Check three forms of duplication
First, check stage duplication: concentrate and oxide may share the same feed. Second, check organisational duplication: a group total may already include a subsidiary's plant. Third, check time duplication: an annual result may already contain quarterly figures. Each requires a different correction, so record the reason a row is excluded rather than deleting evidence without explanation.
Also separate actual output from a future expansion. Announced capacity is not additive to current production unless the analytical question explicitly concerns a future scenario and the overlap is understood. A larger spreadsheet should not automatically produce a larger supply total.
Illustrative aggregation error
A research table contains 1,000 tonnes of reported oxide output and 800 tonnes of downstream metal made from that route. Adding them to obtain 1,800 tonnes of rare-earth supply mixes products and potentially counts the material twice. Keep both observations for their respective stage analyses rather than forcing them into one total.
Three checks before summing
| Possible overlap | Question |
|---|---|
| Process stages | Is this the same material after conversion? |
| Corporate scope | Is the plant already in the group total? |
| Reporting periods | Is this quarter already in the annual number? |
Your review checklist
- Define the aggregation boundary.
- Match chemical and product basis.
- Resolve group and facility overlaps.
- Retain excluded records with a reason.
Investigate with Oreline
Oreline keeps facilities, production stages and observations connected so your team can inspect potential overlaps. Use that context before building a total or comparing the scale of alternative supply routes.
Follow the evidence through the supply chain.
Explore Oreline’s guided investigations. No account required.
Explore the sandbox →Frequently asked questions
Should downstream capacity be ignored?
No. It matters as a separate capability and potential bottleneck. It should not be added to upstream tonnage as though it were new feedstock.
Can a group total and site total both be retained?
Yes. Preserve both with their scope and avoid summing them unless the relationship between the figures is known.