You have activate a Org Unit XYZ with Business Residence attribute and observed that the Site that is created from this activation is XYZ_1 instead of XYZ.
Moreover, you have observed that there is already a Site with ID XYZ but this cannot be used in any of the logistics related documents due to below error message:
Product Recipient Party is missing
Ship-to site not valid
No valid planning data exists for product ABC in site XYZ
The actual system behavior of Site creation is that, when a Business Residence is activated in Org Structure, the Site will be created with the same ID as Org Unit but there are two possibilities that the Site ID may vary from the Org Unit ID. They are,
1. If there is a site/location already exist with the same ID as Business residence/Org Unit then "_1" will be added to the new ID.
2. The second scenario could be, you have activated the Business Residence (XYZ) and Site (XYZ) was created out of it. Later point in time, the Business Residence was deleted and the changes were activated. Again you assign the Business Residence to that Org Unit and activated it again. Now the site ID will be XYZ_1 and site XYZ cannot be used.
This is expected system behavior,
For the first scenario, you can use either XYZ or XYZ_1 based on purpose of creatining of these Sites.
For the second scenario, you can use XYZ_1 for further usage of the Site and Business Residence.
KBA , AP-CR-CR , Customer Requirement , How To