EPCIS Basics Intermediate

EPCIS Event Types Explained

Deep dive into the four EPCIS event types: ObjectEvent, AggregationEvent, TransactionEvent, and TransformationEvent.

TraceHub Team January 01, 2024 Updated Jan 14, 2026 177 views

Understanding EPCIS Event Types

EPCIS defines four distinct event types, each designed to capture specific types of supply chain observations. Understanding when and how to use each type is crucial for proper track and trace implementation.

1. ObjectEvent

The most common event type, ObjectEvent records observations about one or more objects (products) at a point in time.

Common Uses:


Key Fields:

eventTime: When the event occurred
eventTimeZoneOffset: Timezone of the event
epcList: List of EPCs (e.g., SGTINs) involved
action: OBSERVE, ADD, or DELETE
bizStep: Business step (e.g., commissioning, shipping)
disposition: State of objects (e.g., active, destroyed)
readPoint: Where the observation was made
bizLocation: Business location

2. AggregationEvent

Records the association or disassociation of objects - typically when items are packed into cases or cases onto pallets.

Common Uses:


Key Fields:

parentID: The container (SSCC of case/pallet)
childEPCs: The contained items (SGTINs or SSCCs)
action: ADD (pack), DELETE (unpack), or OBSERVE
bizStep: Usually 'packing' or 'unpacking'

3. TransactionEvent

Associates or disassociates objects with business transactions like purchase orders or invoices.

Common Uses:


Key Fields:

bizTransactionList: List of business transactions
epcList: Products associated with the transaction
action: ADD, DELETE, or OBSERVE

4. TransformationEvent

Records when input objects are transformed into output objects - less common in pharmaceutical distribution but important for manufacturing.

Common Uses:


Key Fields:

inputEPCList: Products consumed
outputEPCList: Products created
transformationID: Links related transformations

Choosing the Right Event Type