Lot traceability and genealogy record

Identification, status and traceability

Three ideas that are easy to blur. Identification says what a thing is: part number, revision, lot or serial. Status says whether it may be used: awaiting inspection, accepted, rejected, on hold. Traceability is the ability to follow its history, application or location through recorded identification. A part can be well identified and still untraceable if nobody recorded which lot went into which assembly.

Traceability is what makes a problem small. If a supplier warns that one lot of cells is bad and you can say exactly which 210 units contain it and which three customers have them, you contact three customers. If you cannot, the recall covers everything built in the period, and that is a far larger, costlier and more alarming event.

Forward and backward

• Forward trace (top down, "where did it go?") starts from a suspect lot of material or components and follows it through every subassembly and finished lot to the shipments and customers. It sets the boundary of a containment, correction or recall.
• Backward trace (bottom up, "what went into it?") starts from a unit, usually one returned in a complaint, and follows it back to the component lots, the equipment and the records of its build. It is the first step of most investigations.

Auditors test traceability both ways. Pick a shipped serial number and ask for its component lots; pick a receiving lot and ask where it went. How long the answer takes says as much as the answer.

Reading the record

• Mixed lots. When a finished lot was built from two lots of the same part, and nothing records which units got which, every unit in it is in scope. The tool flags these. Serial-level records, or not mixing lots at a workstation, narrow future recalls.
• Stock not yet shipped. The trace shows what left the building. Units still in stock, in work in process or in returns must be found and held too.
• Gaps. A shipment with no customer, a lot that appears nowhere, or a unit with no inputs is a hole in the record. In a recall, a hole is filled with "everything".

How much traceability?

Traceability costs record keeping, so the level is set by risk and by regulation. Commodity hardware may be traced only to a receiving date. A critical component of a medical device is usually traced to the lot, and an implantable device to the serial number and the patient. ISO 13485 (7.5.9) requires a documented traceability procedure, with the extent defined by the organization and records of the components, materials and work environment for implantable devices. Pair this record with corrective action and nonconforming material controls so a suspect lot is segregated as soon as it is found.

On the exam

CQPA IV.E asks you to describe identifying material by lot, batch, source and conformance status, including the impact on recalls, and to preserve the identity of a product and its origin. CQE IV.B.1 asks you to distinguish identification, status and traceability and apply them (Analyze). CMDA III.D.5 asks you to use methods for identifying and tracing product through receipt, production, distribution, installation and servicing (Apply), and CMDA III.E covers recall, corrections, removals and tracking. Expect a scenario that asks which records let you bound a recall, or what a forward or backward trace would show.

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