Cond parameter is very important in JCL. COND controls the flow of steps. We can do it in the JCL, in the in stream procedure, and in the catalogued procedure.
//Myjob JOB (Acct),’me’, CLASS=A,MSGCLASS=0,
//Step1 EXEC PROC1
//Cond1 IF RC=0 THEN
//ESTEP1 EXEC PROC2
//ESTEP2 EXEC PROC3