Starting DCAS from an MVS procedure requires that the user ID from which it is started have access to the MVS.SERVMGR.DCAS resource in the OPERCMDS class. To provide this access, use the following commands:
RDEFINE OPERCMDS (MVS.SERVMGR.DCAS) UACC(NONE)
PERMIT MVS.SERVMGR.DCAS CLASS(OPERCMDS) ACCESS(CONTROL) ID