2.3.1.2 Automation

VSE customers who use OCCF and/or ISV products to provide console automation functions will find enhanced function in the OS/390 environment. Because of the availability of functions such as DFSMSrmm and DFSMShsm consideration will have to be given to how to best implement these functions, starting with the development of storage and media policies. ISV products also exist in the OS/390 environment to provide additional automation capabilities.

2.3.1.3 Console Operator Interface

VSE console operators tend to have a significant amount of interaction with the system console. This can be referred as a ′chatty′ interface. Many batch applications depend upon operator responses to function correctly. For example, an operator may be required to enter date information and response verification in order for a program to continue. Such facilities are not provided in OS/390 requiring these type of applications to be redesigned.

OS/390 provides the Message Processing Facility (MPF) which controls console message processing and message display. MPF is similar in function to VSE OCCF.

2.3.1.4 JCL Processing

VSE JCL syntax and structure is very forgiving and flexible. Users often exploit this capability to enhance user productivity. For example, users often intentionally code invalid JCL statements so that they may appear on the system console for the correct information to be entered. This, then, provides a somewhat crude way of creating dynamic JCL decks. This capability exists because of the manner in which VSE POWER performs JCL processing. POWER does JCL syntax checking at job execution time. When an invalid statement is encountered the console operator is given the opportunity to enter the correct statement. OS/390, however, does not provide such a capability because of the way JES is designed. With JES, JCL syntax checking is performed at job submission time. Jobs with invalid statements are rejected at this point and, therefore, not executed. Consideration will need to be given to POWER jobstreams that are designed in such a manner.

2.3.1.5 Management Disciplines

Because of OS/390′s enhanced systems management capabilities, thought needs to be given to system management, and its various disciplines, and how it will be implemented in the OS/390 environment. OS/390 provides functions and capabilities in each of the systems management areas. Specifically these are:

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Change control Problem control Performance management Capacity planning Configuration management

Chapter 2. Sizing the Effort

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IBM OS/390 manual Automation, Console Operator Interface, JCL Processing, Management Disciplines
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OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.
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