Architecting and designing : Business Process Analysis (BPA) : BPEL generation : BPEL to BPMN mapping reference : BPMN to BPEL mapping for Composite Process mappings
  
BPMN to BPEL mapping for Composite Process mappings
You can generate BPEL code for BPMN Composite Process mappings.
Pattern
BPMN comments
It is perfectly legitimate and permissible for processes to be highly complex in their structure. In order to treat these effectively the composite process must be reduced to its component patterns and each pattern subjected to its respective treatment. What is important is the order by which the patterns should be treated.
The order is as follows
1 "Receive" or "Send" or "Service" process Task Type for the compound process.
2 All other process Task Types.
3 "Intermediate Boundary Events" for the compound process.
4 "Process Scope". Only if not already included as part of the treatment of "Intermediate Boundary Events".
5 "Children Activities", they reside within a Scope element if one is already declared.
6 "Process Parallel Split"
See also
BPEL to BPMN mapping reference