Need shut down of the database cleanly before it is shut by ohasd while server stop

My requirement is to cleanly shutdown the Oracle database before stopping the server. I checked the log file, and when i am shutting down the server, the database instance is getting terminated(aborted) by OHASD. But i don't want my database to get aborted rather shut down cleanly. To achieve that, i wrote my own script to do the shut immediate of the database and made it as a service(I used systemd). But instead of using after clause in the UNIT, the database is still getting aborted by OHASD. Below is my systemd script.

[Unit]

Description=DB Services

After=oracle-ohasd.service network-online.target