Every manual spreadsheet is an operational risk waiting to scale. In mid-market companies doing $50M+ in annual revenue, it is not uncommon to find critical parts lists, production schedules, and dispatch plans managed in single-user Excel files passed back and forth over WhatsApp or shared network drives.
The Problem: Silent Cell Corruption
When five people edit a workbook with VLOOKUP formulas, someone eventually drags a formula down one row too far or pastes formatted text that coerces numbers to strings. Nobody notices until month-end inventory reconciliation is off by $42,000.
What I Tried and What Failed
We initially attempted cell-locking scripts and Google Sheets protection rules. Floor supervisors found workarounds within 48 hours because real factory shift changes require speed, not permissions modals that lock their screen.
What Actually Worked: A Postgres Ledger with Staging
We replaced the workbook with an internal web app backed by PostgreSQL. Shift supervisors input three numeric fields into tablet-optimized forms. Constraint checks validate yarn lots and loom status in real time before inserting immutable journal records.