"SCCM 1511 CAS Server Installation Step by Step PDF" this document will help you to install Microsoft CAS server with all the steps. If you are planning to build SCCM 1511 Central Administrative Site Hierarchy infra stature, then you should have install a a CAS server. Here I have explained step by step installation to building a CAS server infra stature for SCCM 1511.
I would to inform that go to my other document which is explained about SCCM 1511 Hierarchy for Central Administrative Site Installation.
For more details for Central Administrative Site for SCCM 1511 below is link.