The BPMN2 validation rules included in the BPMN2 Completeness validation rules suite are described in the table.
| Validation rule | Severity |
|---|---|
An Intermediate Boundary Event should have an outgoing Sequence Flow. | Info |
| An Intermediate Event should have an incoming or outgoing Sequence Flow. | Info |
| An Error Code should be specified for an Error End Event. | Info |
| An Event-Based Gateway should have two or more outgoing Sequence Flows. | Info |
| An Event SubProcess will have one Start Event. | Warning |
| A Start Event shall have at least one outgoing Sequence Flow. | Warning |
| An Intermediate Event can have either an incoming or outgoing Message Flow. It cannot contain both. | Warning |