Almost all JES2 initialization statement definitions can be changed by operator commands. These commands are available to both operators and system programmers to allow them to change current definitions. The system programmer can implement certain security features or customization techniques to limit the degree of control an individual or group can have over the operating system.

As your JES2 complex becomes more sophisticated, you might connect your system to others to form a network of systems. You can use operator commands to control the lines that connect the separate systems and define the separate systems to yours. This is typically a very dynamic environment, as different systems are added or deleted from the network because of maintenance, hardware reconfiguration requirements, workload balancing, or to access a database at a different location. JES2 permits you to use commands to alter most of your original network definition, as required.

If this dynamic control were not available, the operator or system programmer would need to change the initialization data set definition, stop JES2 processing, and then restart the system so those changes can take effect. This is, of course, required when redefining some areas of processing, but it denies system users valuable time.