When testing mainframes you should consider the different levels at which you can test, as well as where within these levels you can implement test automation to achieve a low-risk, efficient release cycle.
If you haven’t already, read our blog post on modernizing mainframe development to learn why test automation is an essential ingredient in optimizing the processes surrounding mainframe development and testing.
The first and lowest level at which you can test is unit testing. Unit testing is about testing individual components of the larger system, which for mainframes typically means testing COBOL programs and individual paragraphs of code.
You can automate unit tests to achieve a more efficient ‘assembly line’ in your mainframe development that allows you to test more, in less time, and with higher accuracy, resulting in less faulty code being passed down the assembly line.
For this you’ll need a testing tool that can read the unit tests, and aren’t GUI-based.
The next level of testing is integration tests. As the name implies, the purpose of integration tests is to test interactions with interfaces and integrations between programs within or outside the mainframe.
Integration tests are not to be overlooked; you may have two functioning unit tests, but without testing the integration between the two, you cannot know that they function together - just like if you have two drawers that work just fine on their own, but when set up next to each other, fail to function as intended.
Despite their importance, integration tests are sometimes overlooked, typically due to time restraints and bottlenecks. Again, test automation can help solve this problem.
With automated tests that run across programs in the mainframe, it can be checked that transactions go through as intended, programs run smoothly together, and database calls go through unchallenged.
System tests are designed to test the full integrated system and check that it complies with the specified requirements. Here, you test not only the mainframe, but the applications the mainframe is connected to, for instance, the customer-facing UI app, the enterprise service bus interface, the transactions, and the database.
This type of testing is quite comprehensive, but can be eased with test automation.
By setting up end-to-end tests that run across applications and technologies, a high test coverage can be achieved with minimal human resources. Instead of spending their time on manual test execution, testers can focus on test design and improvement, which can have a significant positive impact on the end-user experience.
With a code-free automation tool, any mainframe expert - regardless of their automation expertise - can set up the tests. As a result, dependencies are removed and teams can flow through bottlenecks in the testing and development pipeline. The developers who have mainframe expertise can then spend their valued time and skill on actual mainframe development.
The last step in the testing assembly line is acceptance testing, where the purpose is to assess if the system is ready for delivery by evaluating whether it complies with business requirements and regulations.
The goal here is to check that the system lives up to set criteria, and that it performs as intended for end-users.
Once again, test automation, and particularly no-code test automation can significantly improve quality across the board.
This type of testing is sometimes done outside the testing and development team by support, product management, or other relevant teams, which supports the case for using a no-code automation tool, because anyone - technical experts and business experts can understand the tests.
In conclusion, it’s possible to increase the quality and confidence in the mainframe delivery pipeline by introducing automated testing throughout the different testing levels.
By doing this, issues can be detected earlier, reducing costs and lowering risk.
In effect, businesses can deliver better value to their end-users faster.