Hi
You can add one more phase in your dep key with base method 0017(immediate depreciation)
Basically, assign a changeover method in dep key based on useful life. As soon as useful life is over, system will switchover to 2nd phase of depreciation key which will be based on 0017
Another option is you directly assign a dep key based on 0017 to such assets and they should depreciate in next month. I prefer 1st option
Ajay M