Hi,
I think you can wirte a z-report to get the Contract id.
The logic will be:
1. call FM CRM_ORDER_READ to read service request get et_doc_flow. Or you can call FM CRM_DOC_FLOW_READ_DB to get ET_DOC_LINKS.
2. From et_doc_flow (or ET_DOC_LINKS), you can searching by "OBJTYPE_A = BUS2000112" to get service contract GUID.
3. searching table OBJECT_ID by above GUID (GUID)you got in step2 to get the contract ID from OBJECT_ID.
Best Regards,
Bruce