32.4.4.2 Design the MVS Target Output

All the material in this book, including the charts that show functional comparisons of products, is for aiding the analysis of the VSE system to help determine the target OS/390 system. It is during conversion team meetings that these items are presented, challenged and designed.

For project organization and planning, the effort is normally divided per type of application item (JCL, code and files), per type of application (batch or online), and per language (COBOL, Assembler, RPG II, and so on). The design of the OS/390 target material complies with the selected standards and operations procedures for the OS/390 target production.

The conversion specifications are documented in a Conversion Specifications Document that becomes the guideline for custom-modifying the conversion tools and developing or custom-modifying additional conversion tools.

32.4.4.3 Determine the Method to Get from Source to Target

Determining the method to get from source to target is the outcome of these discussions with the conversion team. The outcome becomes the basis for your conversion plan.

There are also implications on OEM products that perform functions such as Report Manager, schedulers and backup utilities. Include these topics in your discussions.

32.4.5 Phase 3: Customization or Development of Conversion Tools

This section is specific to the conversion tool. Customizing the tool is unique to the mass migration method and is a cornerstone of the Cortex tool. In the Cortex method customization is how you deal with exceptions or what you do when you don′t like the tool′s output. In Cortex, you modify the tool and rerun your input.

The objective of this task is to adapt the conversion software or develop additional conversion tools to be able to automatically convert all or most of the VSE material to OS/390, and deliver OS/390 material that complies with the selected OS/390 standards and operations procedures.

The custom modification of the automated conversion process follows the specifications documented in the conversion specifications developed above. It is implemented through the positioning of conversion tools options, design and coding of exit routines, design and coding of ad-hoc pre- or post-processors which are then added to the automated conversion process.

Similar to the definition of specifications, this effort can be divided for better project planning and organization per type of application item, between batch and online and per language.

The customization is validated by converting representative samples of VSE programs and JCL and verifying that the local VSE syntax has been replaced by the appropriate OS/390 syntax.

The Custom Modification phase, which begins simultaneously with the second third of the specifications phase, is typically completed in two to four months. The Custom Modifications tasks include:

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IBM OS/390 manual Phase 3 Customization or Development of Conversion Tools, Design the MVS Target Output
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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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