Relationships
In object-centric process mining (OCPM), relationships describe how events and objects are connected inside an object-centric event log, for example, which invoices belong to an order or which deliveries fulfill it.
According to the OCEL 2.0 specification, OCPM supports two fundamental types of relationships:
Event-to-object relationships
These relationships link events to the objects they involve.
Every event must be linked to at least one object.
A Create invoice event may relate to:
an Invoice object
an associated Order object
Object-to-object relationships
These represent connections between objects, even if no event directly mentions them.
They describe structural or business linkages.
A Sales Order related to multiple Sales Order Items
A Shipment related to multiple Orders
This type is what makes OCPM fundamentally different from case-centric models: an event can belong to multiple objects simultaneously. These relationships are essential for understanding dependencies, data transfers, and many-to-many relationships, and form the basis for meaningful object-oriented analysis.
Qualifiers
Both types of relationships can be qualified. For example, the role a particular object plays in an event, for example, the actor, can be distinguished in the event log.