Ibase No not getting determined in CRM Service Order.

Hello All,

I have created a warranty material in SAP CRM, I have also created the main object in installed base and assigned a subordinate object to it, under relationships of the subordiante object I have assigned my warranty material, now when I am creating the service order in SAP CRM when I enter the product id of the subordiante object and the customer the Ibase No is not getting determined, any inputs would be highly appreciated.

Kind Regards

Atul