There is software , some built in the OS and many after market that can do in system "house cleaning " and testing. One example is PC Alert. It shows up as a small open eye in task bar and when We move mouse over it, it reads out my CPU temp. If I right click it and go to the main page, I can test the inter system of every function of my computer as well as all the external systems as well. An inter system test, for example, could be a memory map, showing what is in memory at that moment.
Another is a test of my fans, speed, efficiency etc. It basically is the way you find out if the inter system is working with out any problem and is a big help when you do have a problem in finding a fix for it.
Determine Proper parameters and data are correctly passed between the applications. Documentation for involved system is correct and accurate.Ensure Proper timing and coordination of functions exists between the application system.Develop test transaction set in one application and passing to another system to verify the processing.
Entering test transactions in live production environment and then using integrated test facility to check the processing from one system to another.Verifying new changes of the parameters in the system, which are being tested, are corrected in the document.