A stock transfer between sites only works when one record moves the stock out of the sending site and into the receiving site at the same time, at an agreed cost, with both managers signing it off. Spreadsheets, WhatsApp messages and paper notes rarely manage that. They capture one end, late, at a guessed value.
For a single site, month-end stocktake is straightforward. Someone counts the stock, checks the numbers, and the report goes out before the next trading period starts. Add a second site, and the picture changes. Add ten, and the process either has a structure or it has a hole.
