Prepare a manual comparison of two supplier registers

Decide what a comparable pair means

Align sample identity, method, unit and context so the resulting difference is worth investigating.

Our public material-register example shows a synthetic report beside downloadable output. Use it to inspect how values and source references travel together. The self-service ParseMill trial is for invoice PDFs; supplier test reports and engineering review need a separate fit discussion.

Record the property name, specimen or lot identity, method label, result basis and source unit before pairing values. A matching label is a candidate relationship, not proof of technical equivalence. Keep a separate decision for whether the proposed pair is suitable for the intended use.

Prepare a manual matching sheet

Use columns for left source row, right source row, matching evidence, unresolved context, comparison status and reviewer. Microsoft: Merge queries overview explains that a software merge matches values in selected columns. That operation can organize already verified keys, but it cannot establish that two differently named tests measure the same property.

For an initial comparison, review candidate pairs manually and retain unmatched rows from both suppliers. Avoid sorting each sheet independently and subtracting adjacent values. One missing row would shift every later comparison while still producing plausible numbers.

Try three different pair decisions

Synthetic example: registers A and B contain the following invented records. The worksheet records readiness rather than a supplier ranking.

A7 and B4 have equal displayed values, but equality does not remove the context checks. A8 and B5 cannot be treated as equivalent by changing a column heading. A9 remains visible in the comparison population even though no arithmetic can be performed.

Preserve units before normalizing

NIST: SI notation checklist calls for clear value-unit association. Carry units on each paired record so copying a row does not detach it from a heading. Put any approved conversion in a derived column with its formula, input unit and target unit. Retain the reported values unchanged.

A qualified reviewer should resolve different methods, sampling conditions or material bases before interpreting a difference. Do not let a fuzzy text match settle those questions. Record why a pair was accepted or rejected, including the source passage used to decide. If a report changes, reassess every pair that depended on its earlier version.

Check the comparison is complete

Count accepted pairs, held candidates and unmatched rows on each side. Reconcile those counts to the source inventories, allowing for explicitly documented one-to-many relationships. Ask another reviewer to reconstruct one accepted pair and one rejected pair without using your memory.

Use ParseMill’s material-register example to assess whether source references and raw units survive extraction. Prepare the manual pairing sheet afterward. A tidy export supports comparison work; the match decisions and technical interpretation still need their own evidence and review.