SPOF for CI & ASCS Instances

Dear Guru's,

We have upgraded from SAp ECC 5.0 to ECC 6.0 with Unicode.We have Db Instance(cluster) in one host

CI &ASCS Instances are in one host which are in cluster mode.

Is it possible for SPOF for my CI & ASCS Instance(both are in single host).

Could you please suggest me.

Is it possible for switch over & Fail over scenario's.

Thanks & Regards,

Srini