z/OS system

The job of the z/OS® system programmer is very complex and requires skills in many aspects of the system. The role of the z/OS system programmer can vary from one installation to another, but usually includes installing, customizing, and maintaining the operating system. In most large z/OS installations, system programmers become specialists for only specific tasks.

Generally speaking, the system programmer is responsible for managing the mainframe hardware configuration, and installing, customizing, and maintaining the mainframe operating system. System programmers ensure that their installation's system and its services are available and operating to meet service level agreements. Installations with 24-hour, 7-day operations need to plan for minimal disruption of their operation activities.

The role of system programmer usually includes some degree of involvement in all of the following aspects of system operation shown in Figure 1.

Figure 1. Some areas in which the system programmer is involved

"Separation of duties" enables specialization

In a large z/OS installation, there is usually a separation of duties both among members of the system programming staff, and between the system programming department and other departments in the IT organization. A typical z/OS installation includes the following roles and more:

z/OS system programmer
CICS® system programmer
Database system programmer
Database administrator
Network system programmer
Automation specialist
Security manager
Hardware management
Production control analyst
System operator
Network operator
Security administrator
Service manager

In part, the separation is an audit requirement– ensuring that one person does not have too much power on a system.

When a new application is to be added to a system, for example, a number of tasks need to be performed before the application can be used by end users. A production control analyst is needed to add batch applications into the batch scheduling package, add the new procedures to a procedure library, and set up the operational procedures. The system programmer is needed to perform tasks concerned with the system itself, such as setting up security privileges and adding programs to system libraries. The programmer is also involved with setting up any automation for the new application.

On a test system, however, a single person might have to perform all the roles, including being the operator, and this is often the best way to learn how everything works.