32.1.3.7 Two Phase Approach

The migration project can be broken into a few logical pieces that may help its execution. One method that has been successful is to begin with a mini project, phase 1, to identify and resolve your inventory. Proceeding with a known inventory will allow more precise cost analysis (time, people resources and so on). The cost of a conversion is based on inventory. It also provides information about the effort that may be required to recreate source materials. There are tools and service providers that perform these services. The second phase is the actual implementation.

The Phase 1 output is also a standalone deliverable that can be very useful for Year 2000 preparation.

32.1.4 Assumptions

For the purposes of providing more specific guidance for conversion projects, an approach to the migration had to be determined. This is also true for the migration effort itself, an approach must be adopted. The topics discussed in the Conversion and Implementation Phases of this chapter required that a choice was made. In these discussions, we will describe the environment associated with using Mass Conversion methods and tools. More specifically, the Cortex Migration System (MS) methods and tools will be used.

32.2 Mass Conversion - Background, Benefits and Method

32.2.1 IBM MVS Migration System - Background

The IBM MVS Migration System (MVS-MS) was a conversion aid IBM licensed and sold in the mid 1980s through the mid 1990s that consisted of both a conversion method and a conversion tool.

IBM licensed this conversion aid from SISRO and sold it as the IBM MVS Migration System. When sold through SISRO the aid was, and is known as the Cortex Migration System (Cortex MS). Remote support (via telephone) for MVS MS and Cortex MS was and is performed by SISRO for the Americas and by SISRO SA for the rest of the world.

IBM stopped licensing the Cortex tool in the mid 1990s. Although there have been many changes to the MVS and VSE operating systems and improvements to the conversion tool, the methodology of planning and execution of the conversion has not changed significantly. Today, the Cortex MS tool remains available from Sisro Inc..

A collection of documents including the MVS-MS Planning Guide and the MVS-MS General Information Manual was produced by IBM to facilitate the planning and execution of migrating from VSE to MVS. These manuals are available through IBM.

486VSE to OS/390 Migration Workbook

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IBM OS/390 manual Assumptions, Two Phase Approach

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.