∙Refer to MVS MS - Production Standards, LB11-8080.

6Translating the programs, taking into account the differences between VSE and MVS for each programming language.

∙

∙

∙

Refer to Part 3, ªConverting VSE Languages to OS/390 Languagesº on page 247.

Refer to the specific program, utility or database section in this book. Refer to 2.7, ªScope of Work and Challengesº on page 32.

7Converting the job control language. Because VSE and OS/390 differ significantly in JCL structure and syntax, methods of data distribution and production methods, JCL conversion is normally the most complex task of any migration.

∙

∙

Refer to Chapter 4, ªJob Control Language (JCL) Differences and Considerationsº on page 69.

Refer to 2.7.3, ªJCL Conversionº on page 33.

8Transferring data files from VSE to MVS.

∙

∙

∙

Refer to Chapter 25, ªPrepare the Migration Environmentº on page 401 for information on system connectivity.

Refer to 32.5, ªConversion Phasesº on page 503. Refer 2.7.4, ªFile Migrationº on page 35.

9Testing converted applications under OS/390.

∙

∙

∙

Refer to Chapter 26, ªTest Environmentsº on page 419. Refer to 32.5, ªConversion Phasesº on page 503.

Refer to Chapter 31, ªDiagnosing System Problemsº on page 473.

10Handling the production workload under OS/390, ensuring the jobs are submitted smoothly while staff is still learning about MVS operations.

∙

∙

Refer to Part 6, ªRunning Your OS/390 Systemº on page 435. Refer to 32.6, ªImplementation Phasesº on page 515.

For a migration process time line that shows the relationship between the various conversion tasks refer to 3.4.2, ªProject Plan Exampleº on page 56.

32.1 Conversion Process Introduction

The following discussions follow the methodology used in the Cortex Migration System (Cortex MS). Migrations using this methodology are implemented through a phased project approach. The methodology has proven to be successful, is well documented, and provides for an orderly discussion of topics.

The conversion process of the migration project can be divided into the following major phases and phase groups:

1Preparation Phases

∙Project Management

∙Application Inventory

∙Conversion Specifications

∙Tool Customization

482VSE to OS/390 Migration Workbook

Page 505 Page 507
Page 506
Image 506
IBM OS/390 manual Conversion Process Introduction, ∙ Refer to MVS MS Production Standards, LB11-8080
Page 505 Page 507

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.
Top Page Image Contents