Extracting just data models from the mainframe application.

[sai-bhargav3322]

Hi,
I would like to extract all the data models (TO classes in java terms) that are present in the mainframe application i want to modernize. I was wondering whether the class diagram of data model and other images related data fields that is present in "diagrams" folder (https://github.com/aws-samples/aws-mainframe-modernization-carddemo/tree/main/diagrams) of this repo are generated by aws transform service. Please help me in understand how I can use aws transform service for this use case.
Thank you.

[pbgunasekar]

I had a similar question and did some checking with CardDemo + AWS Transform.

From what I can see, the diagrams under the diagrams folder are not directly exported from AWS Transform. They look more like they were created by the CardDemo team based on the application analysis, and then checked into the repo. When you run AWS Transform, the outputs (documentation, JSON, refactored Java code, etc.) are stored in S3 and shown in the Transform UI, but they don’t automatically appear in this GitHub folder as PNG class diagrams.

For my data-model use case (similar to TO classes in Java), this is how I understood using AWS Transform:

Put the mainframe source (COBOL, copybooks, JCL, etc.) into an S3 bucket and create a Mainframe Modernization job in AWS Transform pointing to that bucket.

Ask Transform to analyze the code and generate detailed technical documentation. In the docs you get information about copybooks, record layouts, and how data is used across programs.

If you also enable refactor to Java, Transform generates Java code for the modernized application. The generated Java classes (DTOs/entities) can be treated as your data model. From there, you can use your IDE to generate UML/class diagrams or adjust the classes to match your target model.

So, as far as I understand, AWS Transform does not currently give you a ready-made UML class diagram like the images in this repo, but it gives you all the pieces (documentation + Java code) to build or visualize the data model for your own application.

If I missed any built-in feature that exports diagrams directly, I’d also be happy to learn about it.