Let’s agreed about SAP testing types.
Component test. It’s a test of specific function or setting. For example, wage type calculation, enter data into infotype, run report. It’s a process step.
Functional test. It’s a test of a process with several steps. Time report (enter time date, run time evaluation, run time report).
Integration test. It’s a test of contiguous processes, processes passing through different modules. For example, fire with final payroll run, payroll with postings.
User acceptance test. It’s a user test, who accepts the system. It’s a complex test, that covers elements of component, functional and integration test depending on user role.
Regression test. It’s a test of already implemented and production functionality after any system change. Is needed to verify that nothing was broken after system change. Under system change we should understand customizing, ABAP, system update or upgrade or any other changes. For example, payroll rule was changed, tax base could affect other wages.
Stress test (load test). It’s a test of system under high load or high pressure. Let’s say we need to understand system response time when 10, 50, 500, 10 000 users will enter the system for any operation.
What’ve I missed?