The easiest way exclude the data from a system from MICS processing is with the EXCLUDEORGSYSIDS parameter in the prefix.MICS.PARMS(EXECDEF) member. This option is documented in section 2.3.5 of the MICS Planning Installation, Operation, and Maintenance Guide. Data from the original sysids listed on the statement will be excluded from all processing:
EXCLUDEORGSYSIDS aaaa bbbb cccc
Data can be excluded from specific component update steps by using the _USRSEL exit. For example, to exclude data from CICS regions on your test machine, you would place the following code into member $BASEXIT in your prefix.MICS.USER.SOURCE library:
IF ROUTINE = 'DYCICFMT' THEN DO;
IF ORGSYSID = 'TEST' THEN SKIP_REC = 1;
Refer to chapter 22.214.171.124 of the MICS System Modification Guide for more information on the use of this, and other available macros.