What is aggregation?

Aggregation is a technique used in conjunction with serialization that establishes and records the relationship between a serialized object and its container, which also is serialized. Aggregation is most frequently used in the supply chain to place smaller packaging units inside of larger ones, such as cartons packed into cases and cases onto pallets. The aggregation relationship directly mirrors the physical packing of the objects into their container.

Aggregation is not a requirement of serialization, from a procedural standpoint or a legal one. For example, a number of pharmaceutical-industry regulations throughout the world mandating serialization do not also require aggregation. However, although aggregation capability requires some investment and effort to implement, it can confer benefits for the implementer and its trading partners beyond mere regulatory compliance.


Because aggregation usually characterizes a container and its contents (a one-to-many relationship), and because the containers are often seen as superior to the items they contain, familial terms are often used to describe different levels. An item that is packed into a container is referred to as a child, while the container into which it is packed is its parent. In a multi-level scenario, such as unit/case/pallet, the container of the container (the pallet) could be called a grandparent. An item that has not been packed, and therefore has no parent, is referred to as an orphan.


For the manufacturer of a product, it is a reasonable rule that only product that is fully packed for shipping should be considered valid. Because aggregation allows automation systems to be aware of the packed state of objects, it is possible to program those systems to automatically decommission (invalidate) serial numbers associated with orphans. By taking this measure, even if the physical product accidentally is shipped, a check of its serial number will confirm it is invalid, and corrective action can take place, providing an important protection in the supply chain.

For trading partners, one of the biggest challenges associated with serialized product is verifying the serial numbers associated with a shipment. If the data carrier for serial numbers is a barcode or 2D symbol, the only way to physically verify the numbers for packed objects is to remove them from their containers. This would represent a major disruption in the processes of downstream partners of a manufacturer. However, if shipment data include full aggregation information, and given sufficient confidence in the manufacturer’s packaging processes, the partner can infer the presence of lower-level serial numbers by verifying the parents’ serial numbers.

Aggregation can provide an additional check on intrusions in the supply chain such as counterfeiting or gray-marketing. Aggregation relationships between parents and children can be compared to the data recorded during the original packaging of the product. Where these relationships differ, it is an alert that the shipment has been tampered with, and corrective action must be initiated.