The current solution by saving each tabs has some problems.
it is easily possible that a user changes to an other tab and did not save what he already has changed. So he misses these changes. It may be can solved by changing the tab it does trigger save.
Another problem is that a user makes not a valid change and did not recognize this. This tab will never save and he can't see the error message because it is in the wrong tab.
Somhow all data of all "forms" should be send once save is submitted and errors in the form data should become on focus to the user.