Receiving write-back and variances

Receiving happens in WMS; on completion WMS writes each PO line’s received_qty back in full, and variance_qty = ordered − received. Review the differences on the variances page.

Here is the division of labor: the actual receiving (unloading, counting, putaway) happens in WMS on the inbound receipt. Purchase does not do receiving — it only watches the results come back. When WMS finishes a receipt, it writes the received quantities back to the PO lines, and Purchase shows you the difference between what you ordered and what actually arrived.

How the write-back works#

1. WMS receiving finishes: the last step of WMS receiving (receive-complete) fires the write-back.
2. Full recalculation: for this PO, WMS adds up the actually-received quantities (received_qty) from ALL its completed inbound receipts, grouped by product — this overwrites the PO line’s received_qty in full. It is a complete recount, not just "the difference since last time".
3. Variance is computed: variance_qty = ordered quantity − received quantity. Positive means short (you got less than ordered); negative means over (you got more than ordered).
4. The write-back response tells you what happened (ok / how many lines written / error), and lines that did not change are skipped quietly.

The variances page#

• Lists every PO line whose variance_qty is not zero — only lines with a real difference show up.
• A positive variance_qty means short delivery (call the supplier about the missing units); a negative one means over-delivery (decide whether to keep or return the extra).
• The numbers come straight from the WMS write-back — they are read-only truth, not something you type in.