Comparison

OCOM vs BPMN

Executive summary

OCOM and BPMN are complementary, not competing. BPMN models how work flows: the activities, gateways and events of a process. OCOM models the objects that work acts upon, together with their identity, governance and lifecycle. BPMN specifies how work is drawn and executed; OCOM specifies the governed objects that work acts upon, and defines the flow itself only as a Workflow at the Models tier, with no notation and no execution semantics. A BPMN process typically operates on objects that OCOM can define and govern.

Scope

Compared

  • Whether each models process flow or the objects work acts on
  • How each treats state and lifecycle
  • How governance is expressed

Not compared

  • BPMN execution semantics or engine conformance
  • Notation and diagram interchange (BPMN DI)
  • Specific process modelling tools

Terminology mapping

OCOMBPMNEquivalent
ObjectData ObjectPartial
CapabilityTask / ActivityPartial
ContractCollaboration / ChoreographyPartial
PolicyGateway condition / business rulePartial
LifecycleProcess / activity statePartial
Event and Workflow (Models tier)Sequence flow / eventPartial

Conceptual differences

AspectOCOMBPMN
Centre of gravityObject-centric: what is governedProcess-centric: how work flows
TimeObject state over the whole lifecycleOrdering of activities within a process
GovernanceFirst-class: ownership, policy, constraintExpressed indirectly through rules and gateways
ScopeSpans many processes acting on the same objectBounded to a single process definition

Concept coverage

ConceptOCOMBPMN
Process flowCoveredCovered
Object identityCoveredPartial
LifecycleCoveredPartial
GovernancePartialPartial
OwnershipCoveredPartial
EvidencePartialPartial
AI retrievalPartialPartial

Three OCOM cells read Partial rather than Covered (Governance, Evidence, AI retrieval), and the reason for each is recorded in the specification's own register: Governance is a Core Characteristic of every Object that no document defines as one (AO-023); Evidence has no Meta, Models or Language definition, its Definition being reserved for a future version (AO-021); AI retrieval is disclaimed by AI/Context/Context Assembly.md, which prescribes no retrieval algorithms (AO-048). Workflow and Event are defined normatively at the Models tier and carry no Core Vocabulary term record.

Covered: the model defines the concept explicitly. Partial: the concept appears indirectly or by convention. Out of scope: the model does not set out to describe it; a boundary, not a deficiency.

Interoperability

References