Hi Cesar,
BADI UJW_LOCKOUT_SCHEDULE_BADI doesn't change WS. It works instead of WS check. There is a sample implementation that's delivered with it.
For example, in the case described in the blog, author would be able to implement following logic. Connect somehow Entities that should be locked together, for example in MD.Ask user to lock just one Entity. Then when comes check for any entity BADI would check if the main Entity is locked and returns status correspondingly for all connected Entities. This makes WS table smaller and WS check runs faster.
Regards,
Gersh