Note: As per the design, if you remove a site which is already associated with a request, the same will be moved to Inactive sites to maintain the service history of the site.
Steps to make a site Inactive in SDP MSP:
1) Select the site or sites that you wish to make it as inactive, click "Delete Site".
2) You will see a Pop-up to associate your requesters to an active site as below:
3) Once you choose an active site from the drop down "Move to Site" and click "Continue", you will see the below message:
4) After this message, when you click "Cancel" to the popped up window, you can now see the Site "Zoho-Site1" is moved to "Inactive Sites" as below: