R002 — Broken Links
Executive Summary
Key Takeaways
- ✓ R002 flags a formula whose reference no longer resolves — most commonly a deleted sheet, a reference error, or an external workbook link that cannot be confirmed to resolve.
- ✓ It is critical severity and one of five critical-override rules — a single triggered finding caps the model's letter grade below A or B regardless of the numeric score.
- ✓ R002 reads facts the parser has already computed during workbook ingestion rather than re-deriving broken-reference detection independently.
- ✓ Confidence on an individual finding is set higher for unambiguous break types (a reference error, a deleted sheet) than for reference types that are broken with less certainty.
Purpose¶
R002 detects formula cells whose reference no longer resolves correctly — the structural category of error commonly experienced as a broken link: a reference to a deleted worksheet, a deleted named range, a reference-error value, or an external workbook link the parser could not confirm as resolved.
Detection Logic¶
R002 reads broken-link facts the parser has already identified during workbook ingestion, rather than independently re-deriving reference resolution. Each broken link identified during parsing is carried through to this rule together with a reference type describing the nature of the break (for example, a reference-error value or a reference to a deleted sheet). R002 assigns each finding a confidence level based on that reference type: break types that are unambiguous (a direct reference-error value, a reference to a confirmed-deleted sheet) are recorded as high confidence; other broken-reference types are recorded as medium confidence.
Why It Matters¶
A broken reference does not always announce itself. Some broken-link types display a visible error value immediately, but others can leave a formula returning a stale cached value with no visible indication that its actual source no longer exists — the cell shows a plausible-looking number that is, in fact, no longer connected to anything. Because a broken reference can sit anywhere in a formula chain and affect every downstream calculation that depends on it, R002 is one of five rules capable of capping a model's overall letter grade under the SM-2.0 Scoring Methodology, regardless of how high the model's numeric score otherwise is.
Evidence Produced¶
A triggered R002 finding's evidence identifies the specific sheet and cell address of the broken reference, the cell's formula text, and a description naming the reference type and the target the reference was attempting to resolve, so the finding is traceable directly to what broke and how. See the Finding Data Model & Confidence page for the full evidence and provenance model this finding is built on.
Severity¶
Critical. Weight 10.0. R002 is one of five critical-override rules under SM-2.0 (alongside R001, R004, R006, and R023): if it triggers even once, the model's overall letter grade is capped below A or B regardless of the numeric score the weighted formula produces.
Example¶
Trigger. A formula on a Summary worksheet reads =Assumptions!C12, but the "Assumptions" worksheet
referenced no longer exists in the workbook — it was deleted during a later revision without the reference
being updated. The cell resolves to a reference-error value. R002 flags this cell with high confidence,
since a reference to a confirmed-deleted sheet is an unambiguous break.
Non-trigger. The same formula, but referencing a worksheet that still exists and a cell that still holds a valid value. No reference has broken, so R002 does not fire, regardless of whether the "Assumptions" worksheet has since been renamed, moved, or restructured internally — as long as the reference itself resolves.
Recommended Remediation¶
The broken reference is re-pointed to its correct, current target — the renamed or relocated worksheet, range, or external file — or replaced entirely if the original source no longer exists and an equivalent value must be sourced elsewhere. Where the reference pointed to an external workbook, remediation should also confirm the external file is genuinely still the intended source before re-linking to it, rather than mechanically restoring a link to a file that may itself be outdated.
Related Rules¶
R002 shares the Structural taxonomy category with R001, R004, and R006, each published in this same initial phase of the Rule Reference; the remaining Structural-category rules follow in later phases and are indexed on the Rule Reference page as they are published.
Related Articles¶
- Broken Links in Financial Models — the Knowledge Centre's buyer-facing technical guide to how internal and external broken links occur and how they are remediated.
Version History¶
No version-specific changes to R002's severity, weight, or category are recorded as of engine version 2.1.0. This section will be updated in the same edit as any future change to the rule's declared attributes.
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Frequently Asked Questions
What does FMAE rule R002 check for?
Formula cells whose reference has broken — pointing at a deleted named range or worksheet, a reference-error value, or an external workbook link the parser could not confirm resolves.
Why is R002 critical severity?
A broken reference can cause a formula to silently return a stale cached value or an error that propagates through everything depending on it. R002 is also one of five rules whose triggering caps the model's overall letter grade, documented on the SM-2.0 Scoring Methodology page.
Does R002 detect broken links to files outside the workbook?
Yes — external workbook references the parser cannot confirm as resolved are included, alongside internal breaks such as deleted sheets and reference-error cells.
Is a broken link the same as a #REF! error?
A #REF! error is one specific, visible form of a broken reference. R002's scope also includes broken references that do not necessarily display as a visible error value, such as an unresolved external workbook link.
Related Articles
R001 — Hardcoded Cells
R001 (Hardcoded Cells) flags a formula cell that has been overridden by a typed numeric value, in a row where the surrounding cells otherwise share a clear, dominant formula pattern. It is critical severity, carries the highest weight of any FMAE rule (15.0), and is one of five critical-override rules under the SM-2.0 scoring methodology — meaning a single R001 finding caps the model's overall letter grade below A or B regardless of its numeric score.
R004 — Formula Inconsistency
R004 (Formula Inconsistency) flags a formula cell whose logic differs from the dominant pattern the rest of its row otherwise follows — an extra term, a different function, or a shifted reference. It is the general case of R001, catching a different formula rather than a typed constant, and deliberately excludes hardcoded cells from its own sample so the two rules never double-count the same cell. R004 is critical severity and one of five critical-override rules under the SM-2.0 scoring methodology.
R006 — Propagated Errors
R006 (Propagated Errors) flags any cell — formula or hardcoded — whose last calculated value is an Excel error (such as #REF!, #VALUE!, or #DIV/0!). Because an error value is a deterministic, unambiguous fact already present in the workbook, every R006 finding carries high confidence. R006 is critical severity and one of five critical-override rules under the SM-2.0 scoring methodology, meaning a single R006 finding caps the model's overall letter grade below A or B regardless of its numeric score.
FMAE Rule Taxonomy
Every rule in the FMAE structural rule pack declares a category attribute at the point it is defined in source — this is not a classification imposed on the rules afterward for documentation purposes, it is the classification the engine itself uses. Six categories cover all 26 rules — Structural (18 rules), Assumptions Governance (1), Integrity Controls (2), Structural Hygiene (1), Aggregation Logic (1), and Model Governance (3). This page publishes that taxonomy as the FMAE equivalent of a control catalog's classification scheme, cross-linked to the Rule Reference page for each member rule.
FMAE Scoring Engine — SM-2.0 Methodology
FMAE computes a model's risk score as 100 minus the triggered rules' combined weight, normalized against a fixed basis, currently 207.0 under the active SM-2.0 methodology. SM-1.0, the engine's original scoring basis (170.0, covering R001–R021), is retained as a frozen historical reference rather than deleted from the record. Five rules — R001, R002, R004, R006, and R023 — are critical-override rules. If any of them triggers, the resulting letter grade is capped so a model cannot be graded A or B regardless of how high its numeric score is. This page documents the exact formula, the versioning between SM-1.0 and SM-2.0, and a fully worked example.
Finding Data Model & Confidence
Every FMAE finding carries the same fixed structure — which rule triggered it and that rule's identity at the time it ran, its evidence, a narrative explanation, and a confidence label of high, medium, or low. Confidence is a deterministic categorical label derived from how strongly a row's cells agree on a pattern, not a machine-learning probability estimate. Stating this plainly matters, since describing FMAE's confidence as AI-derived or probabilistic would overstate what the engine actually does.
Broken Links in Financial Models
Broken links in financial models are references to cells, ranges, or external files that no longer resolve correctly. They occur in two forms: internal broken links, where a cell references a named range, cell address, or worksheet that has been deleted or renamed within the same workbook; and external broken links, where a cell references a cell or range in a separate workbook file that is unavailable, moved, or renamed. Both types can cause formula cells to return errors or silently retain stale cached values, distorting model outputs without visible indication to the user.