Before any test approach is designed, we basically foresee and analyze what could be the possible challenges which is relevant to that specific application/interface or infrastructure.

As we are talking about Mainframes, we can basically foresee some of the very common factors/challenges like

• Building a Test environment is a difficult task to start with.
• The mainframe application streams use complex processing methods/models, due to the extreme volume of interface combinations.
• As mainframes are usually internal and intranet-based, testing the business operations externally in a user’s perspective is very hard.
• There is a high vulnerability that the approach taken to test other applications may not be structured enough to suite a mainframe-based application testing.
• The test tools which are required for automating mainframe application is a very unique ask and very few tools out there have this capability.

The Test approach should primarily address the need for

• Extensive use of Test Harness and Test Stubs
• Critical focus has been put on Unit testing, for the developers to execute. Unit Test results should be shared with test teams
• Test approach should make sure that all related interfaces are tested.
  Use of structured test automation tools should be considered, Example: QA Hiperstation (which intercepts 3270 Datastreams), Compuware FileAid (for IMS/DB2), QTP (with Terminal Emulator Add-in) for automating a manual process.
• Testing should emphasize on user operations and business objectives.