After a small break , I'm back to Business again 
Multi-Mapping would be very tedious, given the complexity of the request and no. of fields that has to be transformed. I have the following request in Outbound.
<Root>
<Business Partner>
<role>MAIN</role>
<name>Main_BP</name>
</Business Partner>
<Business Partner>
<role>CP</role>
<name>ContactPerson1</name>
</Business Partner>
<Business Partner>
<role>CP</role>
<name>ContactPerson2</name>
</Business Partner>
...
...
...
<Business Partner>
<role>CP</role>
<name>ContactPersonn</name>
</Business Partner>
</Root>
Target should be following way. I.e. For every Contact Person , I need an individual message sent to
1st Message
<Root>
<TargetMessage>
<name>ContactPerson1</name>
<name>Main_BP</name>
</TargetMessage>
</Root>
2nd Message
<Root>
<TargetMessage>
<name>ContactPerson2</name>
<name>Main_BP</name>
</TargetMessage>
</Root>
nth Message.
<Root>
<TargetMessage>
<name>ContactPersonn</name>
<name>Main_BP</name>
</TargetMessage>
</Root>
When I execute the XSLT mapping in STLUS Studio it works fine. It generates n number of individual messages.
However in PI I get the following error
Executing Request Mapping "http://xxxxx.com/xxxxx/IC/OM_COD_COD_ContactPersonSelfIntiateRequest" (SWCV f7f3c160327f11e4b01dffc6ac15312e
Mapping "http://xxxxx.com/xxxxx/IC/OM_COD_COD_ContactPersonSelfIntiateRequest" failed to execute: MappingException: Requested index value not covered by interface configuration
"Transmitting the message to endpoint using connection SOAP_http://sap.com/xi/XI/System failed, due to: com.sap.aii.af.service.mapping.MappingException: Requested index value not covered by interface configuration"