Mainframe migration

Mainframe Migration

Most of the Fortune 500 companies are using Mainframe for some specific services or tasks.

With the emergence of new technologies, they are trying to migrate from Mainframe if it helps their business model.

Mainframe migration case studies suggest that some of the mainframe migration is a failure. The important factors for failures are –

  • Wrong planning
  • Insufficient budget plan
  • A Lot of manual effort
  • Wrong Initial analysis.
  • Performance degradation

You will see few Mainframe migration jobs in Hiring portals across the world.

There are some Mainframe migration projects like –

  • Mainframe migration to AWS
  • Mainframe migration to Azure
  • Mainframe migration to a cloud
  • Mainframe migration to Java
  • Mainframe migration to .NET
  • Mainframe migration to SAP
  • Microfocus COBOL to Java conversion
  • Migrating Data from Mainframe to Oracle

Mainframe migration is not easy

This is the question I can answer even when I am sleeping. First, Mainframe migration is not an easy task and I have seen the kind of challenges that come through.

Some of the migration from Mainframe to Java or any other technologies has failed and companies have to come back to Mainframe again. Most of the companies have seen this common issue while migrating

Mainframe migration to Java

Steps to migrate from mainframe to Java on a higher level 
  1. Identify all the COBOL Programs. It will be like equivalent classes in Java. you have to use a tool for converting COBOL code to Java. Either, you can try to do it manually or create a tool or use an existing tool. Some companies have this tool. Do some research on this
  2. What are the copybooks used? What will the equivalent Java library for that copybook?
  3. Identify all the working storage variables and the equivalent variables in DB2.
  4. Identify all the SECTIONS in PROCEDURE DIVISION. This is the place where the business logic is kept. SECTIONS will be like Function in Java.
  5. Identify all the PROC used in JCL. If there are include members, capture all the include member and PROC and see where they are used.
  6. Code a REXX code to prepare an excel sheet with details like COBOL program, JCL calling the Program. Procedure or INCLUDE group used DB2 plan, DB2 packages, DB2 tables etc.
  7. If it important to capture DB2 table with DCLGEN. It will be helpful to convert to Oracle of MySQL server.

Track the length of the COBOL variables properly.

For Example:
If you captured PIC 9(4) as PIC 9(5), then it creates a lot of issues.

All the above projects require proper planning. You must design a proper algorithm to convert COBOL code to Java or .NET  or any programming.

This is critical to the success of your migration.

Evaluate the performance and how you are going to enhance it. 

Are you able to meet the goals? What happens to the existing employees who are working on your Mainframe project? 

Are you going to fire them or are you going to cross train them to adapt to the new technology?

What is the cost involved?

The most important factor of failure is bad planning done by a bad manager or a bad lead to hiring a  technical expert, an SME who has a great experience and expertise on mainframe migrations.

How to use the existing JCL for migration

JCL runs COBOL programs and they run some utilities.

Sometimes, we miss to analyze this and only focus on COBOL migration but a JCL calls the COBOL Program in most of the IBM Mainframe. so, you have to consider this as well.

Are there utilities like SORT, IEBGENER, IEFBR14, IDCAMS etc used? How are you going to see the equivalent of these? Will the performance increase or decrease?

How to work with COBOL-DB2 migration

If your COBOL code contains DB2 modules, then you need to capture the plan and package name. 

Evaluate all the tables used. Capture all the triggers, cursors etc.

This is going to be a huge project.

How to work with COBOL-CICS migration

Evaluate all the CICS maps if used. What are the main regions in which they are running?

This is such a big task that it cannot be listed here. You have to understand all the COBOL-DB2-CICS programs and understand the workflow and design the algorithm for migration.

You cannot directly use a framework for CICS.


Mainframe migration is a big process. you must follow these steps-
  • Hire an expert on Mainframe who has experience of mainframe migration
  • Do a proper initial analysis properly. This is where you need to invest a lot of time.
  • Monitor the performance.
  • Budget
  • Time

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