Architecting and designing : Business Process Analysis (BPA) : BPMN : Modeling Gateways on BPMN diagrams
  
Modeling Gateways on BPMN diagrams
You can draw and define gateways on BPMN business process diagrams. A gateway is used to model decisions, merges, forks, and joins on a BPMN diagram.
See also
Gateways
Expressing exclusive decisions and merges (XOR)
Expressing Inclusive Decisions and Merges (OR)
Expressing complex decisions and merges
Expressing parallel forks and joins (AND)
Gateway definitions
BPMN