Mass Migration as a Conversion Method, Cobol, Rpg

automated conversion defects. The switchover of an entire VSE production to OS/390 over a weekend cannot be improvised: it requires perfect precision and planning by experienced conversion specialists. The complexity of powerful mass conversion tools makes it difficult to staff with internal

non-conversion-expert staff exclusively, because of the learning curve. Hiring conversion consultants experienced with mass conversions and single weekend switchovers is highly recommended for users who want to migrate large integrated VSE production environments to OS/390 over a single weekend.

3.3.9.1 Mass Migration as a Conversion Method

Mass migration uses the single switchover method of migrating a VSE installation to OS/390. The various conversion tasks that need to be performed using this methodology are described in the MVS-MS and CORTEX-MS documentation. The conversion method, or process, consists of running three conversions:

1.The pilot conversion - a conversion of a small subset of the VSE applications, usually involving all or part of the most important work. The pilot conversion educates project team members, provides the time to define OS/390 standards, code any exits deemed necessary for customizing, and overall prepares the team for the rest of the conversions.

2.The dummy conversion - a conversion of all VSE applications; a process that

is normally repeated many times as changes are made to VSE source materials over the life of the project. This is why ²freezing² VSE application

maintenance is not necessary with this methodology.

3.The actual mass conversion (or switchover) - a conversion of all VSE applications, the switchover of the VSE files and catalogs, followed by OS/390 production operations.

Because MVS-MS and CORTEX-MS documentation guides you in the steps and tasks to be performed, it helps you develop a comprehensive and detailed migration plan for your own installation. The documentation also provides the skeleton migration plan with staffing recommendations - you provide your installation-specific details.

3.3.9.2 Mass Migration Used as a Conversion Tool

Used interactively, MVS-MS or CORTEX-MS is a set of subsystems that are panel driven and use TSO terminals to direct all conversion tasks. The tool translates VSE source programs written in the following languages:

∙

Assembler

COBOL

PL/I Optimizer

RPG II

In addition to translating the above VSE programming language programs into OS/390 source equivalents, MVS-MS or CORTEX-MS, herein after referred to as the tool, also performs the following:

∙ISAM programs are translated to VSAM; that is, ISAM I/O statements translated into VSAM statements.

∙COMREG, CNTRL, and PRTOV functions (VSE functions not directly supported in OS/390) are simulated under OS/390 by the tool¢s simulation routines.

52VSE to OS/390 Migration Workbook

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.

IBM OS/390 Mass Migration as a Conversion Method, Mass Migration Used as a Conversion Tool, Cobol

Models: OS/390