Program clauses that restrict device independence are eliminated; that is, I/O assignment clauses removed from programs, placed in JCL.

Program console interactions (for example, COBOL DISPLAY/ACCEPTs) are removed from being executed at program runtime; rather this input is requested at job setup time via job preparation panels and prompts.

The tool converts VSE JCL (procedures, standard label definitions) and the POWER Job Entry Control Language (JECL) - $$LST, $$PRT, $$PUN, $SLI - into OS/390 JCL jobstreams. VSE uses of standard utilities are translated into OS/390 equivalents - SORT/MERGE, IDCAMS, and IEBGENER utilities.

The tool lists information in cross reference reports that enables the installation to make sure that the VSE input libraries are complete. The information provided includes lists of relationships:

Between JCL and PROC/SLI books

Between JCL (or PROC/SLI books) and programs, PSB, DBD, or FCB definitions

Between programs and called modules

Between programs and copied members or macros

The above data can help the project team determine ²what¢s missing,² ²what¢ s duplicated,² and ²what¢s not used² of the VSE source materials. (It can¢t help the team find missing source, however.) Thus, the tool can assist in one of the most crucial tasks of the migration; that is, reconciling the ²source VSE materials² needed for the conversion process. This is sometimes referred to as the Data Analysis Phase.

In addition to source program and JCL translation, the tool also provides:

OS/390 standards naming convention assistance

Testing facilities to help when testing converted programs

Operator job preparation and submission panels

Exits for the tool customizing purposes

Operator job logging facilities

Online terminal exercises to help in learning the tool operations

3.4 Plan Examples

The following is a sample plan for the migration of ABC Company from VSE to OS/390. ABC Company will be contracting OS/390 services from SER company. CNV Company has been contracted to provide professional migration services and will be using CORTEX-MS.

Chapter 3. Developing the Plan

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IBM OS/390 manual Plan Examples

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.