Software Testing Methodology Question:

Background " Application systems are frequently interconnected to other application system.
" The interconnection may be data coming from another application system, leaving for another application system or both.
" Frequently multiple systems (applications) sometimes called cycles or functions are involved.
Usage " To ensure interconnection between application functions correctly.
Objectives " Determining -
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.
How to Use " Operations of multiple systems are tested.
" Multiple systems are run from one another to check that they are acceptable and processed properly.
When to use " When there is change in parameters in application system
" The parameters, which are erroneous then risk associated to such parameters, would decide the extent of testing and type of testing.
" Intersystem parameters would be checked / verified after the change or new application is placed in the production.
Examples " 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.
Disadvantage " Time consuming
" Cost may be expensive if system is run several times iteratively.