32.2.2 Mass Conversion Overview / Benefits

Mass conversion is the major distinction of the CORTEX-MS process. It results in a single switchover of the entire VSE application portfolio to OS/390 over a weekend. Until the switchover weekend, all converted applications run in production under VSE. By the end of the switchover weekend, all converted applications run in production under OS/390. In the mass conversion, there is no overlap of VSE and OS/390 production.

Cortex MS simplifies migration by automating the conversion of programs and JCL, and the transfer of files from VSE to MVS. It recognizes the differences between VSE and MVS and builds an MVS version of the VSE material.

In the mass conversion, all applications items are converted together, one conversion step at a time. It is the opposite of a traditional progressive conversion, in which all conversion steps are applied to the same application item, one item at a time.

For example, in an item-by-item conversion, each program would go individually through the successive steps of inventory, conversion, compilation/link-edit and regression testing. Instead, in a mass conversion, the entire code inventory (all programs, sub-programs, macros, copybooks, and include books) will first be verified for consistency and completeness. Then it will be converted together in one step, compiled/link-edited together in another step, and finally regression tested.

After each mass conversion step, results are reviewed and validated not just one at a time, but hundreds or thousands of application items at a time. Result validation too, is performed in mass, using summary statistics to classify all messages by occurrence and by severity. Individual manual verifications are conducted on a sample of items that have the same message, to identify by sampling the cause of the message and decide on a global resolution.

The first mass conversion is a pilot conversion. It is used for analysis, rather than for obtaining MVS material. The following mass conversions will be trial mass conversions, which will deliver MVS test material with an increasing quality, as the project and CORTEX-MS custom modification progress. Batch and online may be converted together or separately, as both will progress at a different pace. The final and actual mass conversion will be started after MVS tests have been successfully completed. It will deliver the actual MVS production material. The actual JCL conversion may be scheduled one or two weeks before the actual program conversion, in order to apply final manual JCL modifications. There will also be a special one-time translation of all application development source code, but without any compilation or JCL generation. Every three to four weeks, the mass conversion will start from a fresh copy of the entire conversion inventory, in order to take into account the last VSE maintenance modifications. Between two supplies, additional mass conversions may be executed from the same supply, in whole or in part, in order to take advantage of the latest custom modification improvements.

Key elements of the Cortex-MS mass conversion methodology are:

1.Automated Conversion

2.Repetitive Conversion

3.Mass Conversion (Switchover)

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IBM OS/390 manual Mass Conversion Overview / Benefits

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.