be performed on the VSE side and then sent to OS/390. The determination and collection procedures are developed once and then repeated. The supply is done once per month. Also unique to the Cortex MS environment is that the analysis and resolution work is on going throughout the project.

The Cortex tool produces reports listing missing and unreferenced elements to assist with resolving exception conditions. Those exceptions are reviewed and addressed by VSE production support personnel. There should be no missing elements in the supply of the conversion inventory by the middle of the specifications phase.

Sometimes grouping the exceptions by names provides a clue to their condition. The next step is to analyze why these conditions exist and then resolve the way the supply is produced by adding or deleting members or by changing the supply procedure to pick members or code from other places or edit it. This is an iterative process that is repeated every three weeks during the conversion. The schedule ensures that the supply comes clean and remains clean.

The most common mistake made during inventory validation is to casually delete unreferenced elements. Unreferenced often indicate that something has been missed upstream.

Another common problem is to have production jobs where the JCL resides in someones desk. These can provide ad-hoc jobs that even the scheduler was unaware of. This is also true of jobs that are submitted from remote locations through RJE.

The first task is to validate and correct the procedure for supplying the VSE source material and the design that is included in the conversion plan. A second important task is to validate the VSAM user catalog file definitions regarding VSE/MVS compatibility.

The key point here is that the quality of the final product of the validation is only as good as what is fed to it.

The conversion inventory is mass collected-transferred-verified-converted every two to three weeks from project start to switchover, in order to automatically take into account the VSE application changes. Because it will be repeated many times, this mass processing procedure must be automated to reduce or eliminate the manual effort and to ensure repeatable, reliable and improving quality from a capture to the next one (less or no missing elements).

The application inventory is collected for a final mass conversion a few weeks before switchover. Between this final mass conversion and the switchover, several captures are scheduled to identify (source compare) and carry-over the last VSE application changes. But the changed elements are converted (or their changes are duplicated) one at a time, to eliminate the risk of massive last minute regression with the automated conversion.

32.4.3 OS/390 Standards and Naming Conventions

The objective of this task is to define a set of OS/390 standards and naming conventions for the converted applications.

It is recommended that you define the new OS/390 standards and operating procedures first, at least at a high level, before defining new JCL-referenced

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IBM manual 32.4.3 OS/390 Standards and Naming Conventions

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.