Modeling rules for system-based Enterprise BPMN process diagrams
The model does not contain exactly one pool.
The model contains nested lanes.
The model contains lanes that are outside a pool.
The model contains no lane.
The model contains a pool whose orientation (vertical or horizontal) does not match that in the target diagram.
The model contains elements that are placed outside of lanes (except annotations).
The model contains SAP functions that refer to a specific logical component and not all these SAP functions are placed in the lane that corresponds to this logical component.