You can start CICS® in either of two ways:
Whichever method you use to start CICS, you determine how CICS starts up, and the facilities and resources that it can use, by specifying values for system initialization parameters to be used by the CICS startup procedure. You would normally specify the system initialization parameters that CICS is to use before you start CICS. (See Specifying system initialization parameters before startup.) However, after you have started the initialization of CICS, you can override the system initialization parameters specified before startup; for example, to enable a specific facility for that run of CICS. (See Overriding system initialization parameters during startup.)