With ten SKUs on one sheet, anyone can see who changed a cell. After fifty customers, three warehouses, and tiered prices, the sheet is “correct” in three places at once: sales has the latest price, the warehouse has yesterday’s download, finance still carries a discount that was voided. What breaks is not a software idea. It is the same row of goods that will not match across three files.
The break is usually not “whether people know Excel”
Pivot tables will not stop three things. First, outbound and inbound are not written into the same file at the same moment: the warehouse backfills at night, sales already promised the customer from the book qty that morning. Second, batch, expiry, and multi-bin rarely fit one row, so someone splits the file and someone writes “ship the old lot first” in a note that never enters a formula. Third, price and terms follow the customer, the SKU, and whether the order is rushed — a cell can hold one number. That is not poor Excel skill. A spreadsheet has no state machine. Why spreadsheets and WeChat are not enough is in Why a company cannot run operations on spreadsheets and WeChat alone.
Once volume rises, the sheet punishes the people who still keep it straight
At low volume the warehouse lead remembers whose pallet is whose. After volume grows, that memory is the bottleneck: leave, resignation, or two rush orders at once, and mis-ships start. Chasing blame in a spreadsheet is worse — you can prove a cell changed, not who changed it under what permission. Why operations break when people leave is in Why operations do not fall apart when people leave.
People say: put the file on a drive, share it, add dropdowns. Sharing solves “everyone can see it.” It does not solve “outbound must deduct, you cannot promise a date below safety stock, a special discount must be approved.” Seeing and constraining are different jobs. Using a system as an electronic ledger versus as the work entry is in Spreadsheet management vs. a system: which one can hold the rules. More common still: you bought packaged inventory software whose fields cannot hold your split shipments and free-goods rules — that case is in When SaaS does not match how the floor actually works.
When to stop patching the spreadsheet
Any of these signals means another macro only delays the collapse: the same SKU on several rows that will not match; the books go negative and you still take orders; a customer statement takes two days to stitch from three files; the warehouse starts a notebook for “numbers not on the sheet.” After you stop, phase one does not need a full ERP. Make purchase inbound, sales outbound, and stock locks actions you cannot skip. How we estimate cost and cycle is in What a custom business system costs and how long it takes. DaXi Technology starts from the files you already use and turns the columns that split into document states — not into a prettier master sheet. Bring the current files to the Business systems service page and mark the messy points.