ASCS instance VS CI

hi,

We need to install a production system with Hardware based High Availability(if there is a Hardware failure in Central instance of server A, the Storage from Hitachi will get allocated to Server B and Central instance will start running from Server B. Server B will have a different physical host name, but the same virtual name). This server will have two application servers and the CI.

I was informed that ASCS instance is required for all types of HA systems.

But in my scenario, i think that a ASCS instance is not mandatory, since i am using Hardware based failover and not SAP based/Software based failover

Please advice.

PS: I am aware that ASCS instance contains the message server, enqueue server etc.