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A calculation tool should show not only what each input represents, but where it came from. Power systems engineer Evgenii Buchinskii proposes a deliberately simple model: give each decision-relevant input one provenance class. The labels can help reviewers spot version ambiguity, weak assumptions, hidden overrides, and stale dependent values—but they do not prove that the calculation method is correct.
What provenance classes tell a calculation reviewer
A provenance class describes an input’s source or status, not its engineering quantity. For example, a cable calculation might contain resistance as a quantity; its provenance class says whether that value came from a manufacturer document, a project decision, an assumption, or another source.
Buchinskii’s proposal uses one class per input. It is a lightweight labeling scheme, not a formal IEC or ISO ontology, graph database, or semantic layer. Its purpose is to make the origin and review status of important values visible.
The six classes and the review failures they expose
| Class | What the label means | What it helps a reviewer notice |
|---|---|---|
| Normative | A value or method comes from a clause in a named standard edition. | A saved result may cite a standard without making clear which edition or method it used. |
| Manufacturer | The input comes from a datasheet, catalogue, or type-test report. | A measured value may be confused with a typical value, or the document revision may be missing. |
| Project | The value reflects a decision recorded for a particular project. | A site-specific limit may be mistaken for a general physical constant and reused elsewhere. |
| Assumption | The value was selected because the real value was unavailable. | A weakly supported input may appear as certain as one backed by a reliable source. |
| User override | A user manually replaced a library value. | A changed default may affect results without being obvious during review. |
| Derived | The value was calculated from other inputs. | A dependent value may not update when one of its parent inputs changes. |
Why normative references need an edition
A standard’s name alone may not identify the method behind a saved result. Buchinskii uses IEC 60909-0 as an example: he says its 2016 edition was replaced by the 2026 edition in July 2026. The IEC Webstore lists IEC 60909-0:2016 as withdrawn on 2026-07-23 and identifies IEC 60909-0:2026, Edition 3.0, published on that date. As of October 2026, the IEC catalogue identifies the 2026 edition as the current one.
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The IEC describes IEC 60909-0:2026 as covering short-circuit-current calculations in low- and high-voltage three-phase AC systems operating at 50 Hz or 60 Hz. Its catalogue says systems with highest voltages of 550 kV and above and long transmission lines are outside the document’s scope. A tool following Buchinskii’s recommendation should record the standard identifier, edition or year, and relevant clause, and could warn when a cited edition has been superseded.
How provenance makes assumptions inspectable
An assumption label does not quantify uncertainty or establish that an assumed value is wrong. It makes the value easier to challenge. Buchinskii’s example is soil thermal resistivity in a cable calculation: he says it is often assumed and can strongly affect the result. The article provides no measured distribution or independent sensitivity study, so that example should be read as his engineering observation, not a quantified frequency or effect size.
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As Buchinskii puts it, “Marking it does not weaken the result. It tells the reader where to push.” In a design review, the practical question is “what would have to be wrong for this result to be wrong.” A clearly labeled assumption points to one place to investigate; an unlabeled value does not.
Provenance, audit history, and validation are different
- Provenance records what kind of source or status an input has.
- An audit log records who changed what and when.
- Validation checks whether the calculation method is correct.
These answer different review questions. Provenance alone cannot show who changed a value, and a source label cannot validate an equation. As Buchinskii says, “Traceability tells you where every number came from; validation tells you whether the method is right.” He also warns that “A fully traceable wrong equation is still wrong, and a validated black box is still unreviewable.”
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What a calculation report can show beyond PASS or FAIL
Buchinskii recommends that a report expose the governing criterion, numerical margin against it, and weakest input together with its provenance class. A bare PASS can conceal whether a design has little or substantial reserve: he contrasts illustrative examples of 3% and 40% reserve, not outcomes from a field study.
His example lines show the intended level of detail:
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- Weakest input:
k = 115— class assumption, no source recorded. - Margin: 185 mm² installed against 154 mm² required.
These figures are illustrations from Buchinskii’s article, not measurements from a named project or dataset. In a real report, the criterion and margin should be tied to the actual calculation, while the weakest-input note should identify the value and its class. This makes it easier to compare results than a status label alone.
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Buchinskii frames the problem with a cable schedule that changes from 95 mm² to 120 mm² even though, in the scenario, nothing in the project changed and nobody knows which input moved. This is an illustrative scenario, not a verified incident report. Provenance can narrow the review: a user override suggests checking a changed library value; an assumption suggests revisiting an unsupported input; a derived value suggests checking whether dependencies recalculated; and a normative label prompts confirmation of the cited edition and clause.
The labels do not identify the cause by themselves. A reviewer still needs the input values, calculation logic, change history, and relevant project context. Their benefit is to make the next question more precise.
Where the proposal fits
For calculation-software designers, the six classes offer a small, comprehensible layer of traceability that can appear beside inputs and in exported reports. For engineers and reviewers, they make it easier to distinguish sourced values from decisions, assumptions, and calculations. Buchinskii discloses that he develops IECCalc.com, a free IEC calculator set; that disclosure is not evidence that any specific implementation has adopted or validated this taxonomy.
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