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.