OCEL (Object-Centric Event Log) 2.0 Specification

TL;DR

OCEL 2.0 addresses the limitations of traditional case-centric process mining by enabling object-centric event data that reference multiple objects and permit qualified relationships. The paper presents a formal metamodel, a running example, and three concrete exchange formats (relational SQLite, XML, JSON) with corresponding schemas and constraints. It introduces major extensions such as Object-to-Object relationships, dynamic object attribute values, and qualifiers for E2O and O2O, along with a dense relational storage design. The resulting standard supports interoperability, scalability, and broader applicability of object-centric process mining across domains, while remaining practical for implementation and future extension.

Abstract

Object-Centric Event Logs (OCELs) form the basis for Object-Centric Process Mining (OCPM). OCEL 1.0 was first released in 2020 and triggered the development of a range of OCPM techniques. OCEL 2.0 forms the new, more expressive standard, allowing for more extensive process analyses while remaining in an easily exchangeable format. In contrast to the first OCEL standard, it can depict changes in objects, provide information on object relationships, and qualify these relationships to other objects or specific events. Compared to XES, it is more expressive, less complicated, and better readable. OCEL 2.0 offers three exchange formats: a relational database (SQLite), XML, and JSON format. This OCEL 2.0 specification document provides an introduction to the standard, its metamodel, and its exchange formats, aimed at practitioners and researchers alike.

Figures (4)

• Figure 1: OCEL 2.0 metamodel
• Figure 2: Linking the OCEL 2.0 metamodel to the formalization in Definition \ref{['def:ocelDef']}.
• Figure 3: General relational schema of the proposed relational implementation.
• Figure 4: Relational schema of the running example OCEL 2.0 log.

Theorems & Definitions (2)

• Definition 1: Universes
• Definition 2: OCEL