What a batch is
A batch, or lot, is a quantity of a product made or received together, under the same conditions, and given one identifying number. Everything in the batch shares a history: the same raw material lots, the same production run, the same manufacturing date and usually the same expiry date.
Batch tracking means carrying that number on every document the goods touch, from the moment they arrive or are made to the moment they reach a customer, so that the history can be read back at any time.
Forward and backward traceability
Both answers are only as good as the weakest document in the chain. If the batch is recorded at production but not on the delivery challan, forward traceability stops at your gate.
| Direction | The question | When you need it |
|---|---|---|
| Backward | Which supplier lots and which production run went into this batch? | A customer complains, or a finished batch fails a test |
| Forward | Which customers received goods from this batch, and on which invoices? | A raw material lot turns out to be faulty, or a recall is ordered |
Expiry, shelf life and FEFO
For goods that expire, the batch also carries a manufacturing date and an expiry date. Where the product has a fixed shelf life, the expiry can be calculated from the manufacturing date instead of typed in.
Stock with an expiry is usually issued FEFO, first expiry first out, so the batch that expires soonest leaves first. That is different from FIFO, first in first out, which issues the oldest receipt first; the two give different answers when batches arrive out of expiry order.
Who needs it
- Pharmaceutical manufacturers and distributors, where medicines carry a batch number on the label and a recall has to reach every buyer.
- Food and beverage businesses, where packaged food carries a lot or batch number and expiry is part of the product.
- Chemicals, paints and adhesives, where properties vary by batch and customers ask for the certificate of analysis.
- Any manufacturer whose customers require traceability as a condition of supply, as auto and electrical OEMs often do.
Where batch tracking breaks
- The batch is recorded at goods receipt and production but dropped on the invoice or challan.
- Several batches are issued to one production order without recording how much came from each.
- Returns come back into stock without their original batch, so they mix with new stock.
- Quality holds live on paper, so a rejected lot can still be picked and sold.
In short
- A batch or lot is a quantity made or received together, identified by one number.
- Backward traceability finds what went into a batch; forward traceability finds who received it.
- Goods with expiry are usually issued FEFO, first expiry first out.
- Tracking only works if the batch appears on every document, including the challan and the invoice.