Plant Master Data 

As described in the documentation on Branch - Organizational Unit, plants must be linked to branches. More than one plant can be assigned to a branch.

You can allocate a plant to a branch by choosing the Customizing path for assigning CGC branches.

Before you can allocate the plant to a branch, the plant must be assigned to a company and the CGC company must be maintained.

If either the plant is not assigned to a company code or the CGC company is not specified, the field to enter the branch is not available for input.