What it means
Lots may differ by manufacturing date, supplier, formulation, test outcome or destination, so when a quality alert affects one lot the business must identify and isolate it without stopping unrelated stock. Segregation can use labelled locations, containers, colour cues and restricted system status, but labels must be accurate and readable.
Define which products need lot tracking and at which unit level, since a loose-pick area is often riskier than a sealed pallet because workers can move individual units into the wrong bin. Keep receiving, storage, picking, rework and returns aligned.
If a mixed pallet is unavoidable, document exactly which cartons belong to each lot in a form the next team can use. Scan at the point where a physical lot moves, not only when the purchase order is received, and record what was moved, when, where and by whom, because scanning the wrong label can create false confidence.
Separate identity from disposition: two lots may both be saleable but need distinct records, while a held lot needs additional controls that prevent allocation and shipment. When one lot is partially released, the released and held quantities must remain distinguishable, and cycle counts should test physical labels against the inventory system.
When a quality alert arrives, freeze the affected stock in both the warehouse system and the physical location, trace what has already shipped and what remains, then decide whether to notify customers under the applicable product rules. Do not assume every product category has the same recall duty.
Review lot splits after a supplier substitution or relabelling, because a date code may not be the manufacturer's lot identifier and a traceability chain should not be invented from a purchase-order number if the actual units cannot be tied to it. Test the process by selecting a lot and asking staff to find all remaining units and shipment records; if some cartons cannot be tied back to a source, record the gap and keep them on hold until they can be assessed.
A tabletop exercise can reveal problems before a live incident. For owners, lot segregation limits the size of a recall and avoids unnecessary waste, but it only works when a person can walk to a shelf and pick the exact lot named in the record.
In practice
Real-world examples.
Example
A distributor holds one suspect food lot in a clearly marked cage while other lots of the same product remain available.
Example
A warehouse discovers two lots mixed in a pick bin and reconciles them before fulfilling further orders.
Example
A partial release lists the authorised cartons, while the remaining cartons keep their hold labels and blocked system status.
Formula
Calculation
Lot location accuracy = Lot-labelled storage locations whose physical contents match system lot records / Lot-labelled locations checked x 100
Worked example. An invented warehouse checks 200 lot-labelled locations and finds 194 match the system record.
- Lot location accuracy = 194 / 200 x 100 = 97%.
- The six mismatches need identification and correction before affected stock is picked.
A location-level measure may miss mixed cartons inside a supposedly correct location; sample at the unit level where risk warrants.Case study
Seen in the real world.
This illustrative and entirely fictional example follows Crestline Foods, an invented ingredients distributor. It received a supplier alert for a specific lot, but its picking bins contained units from several deliveries. The inventory system listed the lot, yet staff could not prove which physical packs were affected. Crestline temporarily held the mixed bins, counted and relabelled each pack using original supplier markings, then reconciled the ledger.
It changed replenishment so new lots do not enter a bin until the prior lot is cleared or a segregated space is assigned. The next supplier alert affected a small known quantity instead of a whole product line. Crestline also follows the record forward to past deliveries rather than checking only stock still on site. A warehouse correction cannot retroactively identify an unmarked pack at a customer's site.
It documents the limits of what the original evidence can prove. For the next receipt, staff scan the supplier lot on sealed packs and test a sample against the system location. The quality owner reviews exceptions, including packs moved into loose-pick bins. These checks make the later traceability claim more credible.
Watch out
Common mistakes.
- Relying on system lot data while physical units lack matching identification.
- Treating a purchase order as a substitute for actual lot evidence.
- Allowing held and released units to share an unmarked pick bin.
Questions
People also ask.
Must every product be segregated by lot?
Apply the level of control required by product risk, contracts and applicable rules.
Can two saleable lots share a location?
Only if they remain clearly distinguishable and the system can pick the correct one.
What if labels are missing?
Hold uncertain units and use reliable source records to identify them before release.
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