In the process on installing and configuring CA Common Services (CCS) Tomcat server.
In the section for configuring the Tomcat server's security it appears to assume the server's userid is defined.
Release : 15.0
Component : CCS APACHE TOMCAT
The user that is defined for the Tomcat task to run under must have a valid OMVS segment that includes the same GROUP as the default GROUP of the user ID that installed Tomcat.
A valid HOME directory (eg. /tmp), OMVSPGM (eg. /bin/sh) and UID are requirements.
This user should be the same user as specified for the SRVID symbol in member TOMSEDIT of the CAW0JCL installation library.