The lost acknowledgement
- What arrives
- At Day 16, 12:05 the warehouse system sends receipt R-103 again: same identifier, same 60 units. The warehouse's own count for A, taken at the same instant, says 180.
Receipt R-103
- Expected
- Already recorded
- Observed
- Already recorded matches
- Guard off
- Applied differs
Recorded on hand in A
- Expected
- 180
- Observed
- 180 matches
- Guard off
- 240 (+60) differs
Available in A
- Expected
- 138
- Observed
- 138 matches
- Guard off
- 198 (+60) differs
In transit on AIR-1
- Expected
- 60
- Observed
- 60 matches
- Guard off
- 0 (−60) differs
Received on AIR-1
- Expected
- 180
- Observed
- 180 matches
- Guard off
- 240 (+60) differs
Total tracked for PO-1
- Expected
- 1,200
- Observed
- 1,200 matches
- Guard off
- 1,200 matches
Warehouse count minus ledger
- Expected
- 0
- Observed
- 0 matches
- Guard off
- −60 differs
Reconciliation
- Expected
- Matched
- Observed
- Matched matches
- Guard off
- R-103 counted twice differs
- Recovery
- Retry handled without changing stock. The retry is recognised by its original identifier. No second stock movement is recorded. Identity is the message’s identifier, never its content: two real receipts can carry the same shipment, code, quantity and time.
- The control
- Guard off, the retry makes 240 units in A and an air shipment that looks complete, while the total still reads 1,200. The warehouse’s own count is what catches it, and names the receipt.