Hello @chunsookim,
For the FIT values, please create a support ticket.
If you have any safety related question or if you want to have access to the S12Z Safety Manual and other documentation, please use the SafeAssure NDA community:
https://community.nxp.com/groups/safeassure-nda
https://community.nxp.com/docs/DOC-335524
Regards,
Daniel