INV-10 · When two systems disagree

Two fund-administration exports for the same fund disagree. Find every gap, say what kind of gap it is, and resolve each one without inventing a number. Which system do you trust, and for which question?

FUND-ACME-I: admin-export-a.csv, admin-export-b.csv, and positions.csv. A spreadsheet. AUDIT: if a model is asked to reconcile the files, its output is checked like any other claim.

Joining on name and silently dropping a row. Averaging two numbers instead of flagging the disagreement. Inventing an explanation for a gap. "Fixing" a number with no source. Trusting the cleaner-looking file.

A reconciliation log: every discrepancy with both values, its type (stale value, definition difference, missing record, naming mismatch, timing), the source that settles it or the question that would, and the system of record for that field; totals for each file and how they reconcile; and a note on what a model did with the same files, if one was used.

CT: classifying discrepancies rather than just finding them. CR: building a match key that survives messy names. CO: two students reconcile independently and compare logs. CM: a log a fund controller could act on. CZ: the investors who receive a report built on the wrong file.

A fund accountant or operations analyst reviews the log. Standing instruction: reject any resolution without a source. School-supervised.

R1: one fund, one as-of date. R2: every resolution sourced. R3: comparator is a naive merge. R4: discrepancy types named. R5: the log is actionable. R6: refuses to invent a number.

(a) A clean merged table that hides a dropped row. (b) Gaps "resolved" by picking whichever number looked right.

Lane A (finance or business capstone). Career link: fund operations and administration. No verified credit claim.