Hi Nitish,
You can do this by 2 approach:
1. Create a new fields using AET and Enhance Object SERVICE_CONTRACT. Here you can add your field in any of the business object as follow:
Once added then you can update the fields which are accesble in DO_PREPARE_OUTPUT method of your IMPL class of view enhanced.
2. Another approach is to add a new VALUE node and attribute in the enhanced view and populate the field value.
Let know in case of any issue.
Thanks
Saurabh Kabra