3.2.2.3 Applications Programmers

The applications programmers help the project manager to develop migrations procedures. They also test converted applications. They should be thoroughly familiar with critical applications (both online and batch) and understand both VSE and OS/390. Their tasks and responsibilities include:

Helping to design the specifications for the migration

Analyzing and preparing the VSE source material

Developing any conversion tools or specific conversion procedures

Manually converting some general purpose user routines and programs

Analyzing and solving conversion problems

3.2.2.4 Operations

If a mass migration tool is used, operations personnel will submit and control the mass migration jobs, complete and check the production database, and test the converted applications under OS/390. They must understand the operating procedures of VSE and OS/390, and know how to use the tool. Their tasks and responsibilities include:

Helping to design the specifications for the migration

Designing jobstep preparation

Preparing VSE files and JCL

Implementing conversion and OS/390 operational procedures

Testing the converted applications

Completing and checking the mass migration tool output

Assisting with OS/390 operations

3.2.3 Tasks

It cannot be stressed enough how absolutely important a well thought out and well documented project plan is to the successful completion of the migration project. Discussed here will be some of the key essentials in planning for such a project and some thoughts on how the actual project plan should be developed. Assistance with developing the conversion plan can be found in Chapter 3 of the MVS MS Planning Guide named ²Developing the Conversion Plan². The checklist that was used to develop that plan can also be found in Appendix A , ²The Conversion Workbook² of that publication. An example of a project plan can be found in 3.4.2, ªProject Plan Exampleº on page 56.

Listed below are some of the main tasks that are involved in a migration.

1Defining objectives.

2Analyzing what the tasks required in a migration are and developing a well-documented migration plan.

3Assigning personnel to the conversion team.

4Deciding on a conversion method and a conversion tool(s).

5Analyzing the VSE workload and developing a comprehensive list of the applications to be converted.

6Planning for and upgrading hardware.

Chapter 3. Developing the Plan

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IBM OS/390 manual Tasks, Applications Programmers

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.