1. Pull on-hand from Flexport. Inventory by SKU, by warehouse, by status. Available, reserved, damaged, in transit.
2. Pull on-hand from NetSuite. ERP inventory by item and location. The system of record version.
3. Pull on-hand from Shopify. Storefront available quantity, what the website is showing as sellable.
4. Standardize the SKU and warehouse codes. Trim, uppercase, strip prefixes, map between code systems. Same SKU and same warehouse across systems means same row.
5. Outer join the three sources. One row per SKU and warehouse, one column per system, the deltas calculated in units and percent.
6. Label every row. In sync, Flexport low, ERP low, Shopify low, missing in a system. The label tells operations exactly which side to investigate.
7. Output the report. Full reconciliation table for the record, plus a filtered view of just the discrepancies sorted with the worst dollar exposure first.