What is Inter-System Testing?

Software applications that are being developed nowadays are dynamic enough to interact with each other and to make use of required data from central locations. This means multiple systems can communicate resources with each other. 

While there is an interaction between two or more systems that is called inter-system interaction or interfacing. To check and ensure the integration of functions is working properly Inter-system testing is performed. Let's learn more about Inter-system testing. 

What is Inter-System Testing?

The process of testing the integration functions and integration points between multiple systems that are using a common source of data is called inter-system testing. The main objective of this testing is to ensure that common resources are accessible to multiple systems consistently and accurately as per requirement. As for a single operation, two or more applications are interdependent that's why it is also called Interoperability Testing. It is also called external interface testing.

The objective of Inter-System Testing

• Interaction between applications.
• Sharing and Accessing common data.
• Proper timing and coordination of functions.

How to perform Inter-System Testing?

Inter-system testing can be performed based on multiple instances. The basic check to confirm first is ensuring applications are hosted across locations and dependent on a common set of data/resources. Then ping/communicate with another system for resource dependability and ensure integration points for a single application hosted at multiple locations are working fine and data flow between them is happening correctly. Target should be checking end-to-end control and flow of data in a cycle where the cycle is the involvement of multiple applications in the process.

This test can be performed in many other methods as well like:

• Develop a set of test transactions in an application to pass to a different application verification process.
• By using the integrated test facility entering into test transactions in a live production environment and ensuring test conditions are getting passed from application to application to verify the processing is correct.

The below figure represents how to do Inter-system operation and its testing.

When to Perform Inter-System Testing?

• When there is the dependability of any resources on another application.
• When multiple applications use some set of common data. Then in this case the data which is getting retrieved needs to be compared and verified with the data present in the database.
• When you want to check compatibility between dependent modules of different applications. In many scenarios, systems are not only dependent on data rather on multiple common functions also at that point working of functions needs to be verified as it is getting used by any third-party system.
• When you want to check the communication between applications happens properly with proper parameters. When systems undergo internal changes then internal parameters need to be verified after the change.

Example of Inter System Testing

• You are using Axis bank ATM card to withdraw money from SBI ATM. So here the communication of data happens between SBI and AXIS bank internally after which you only get the cash. That means here two different systems are using some common set of data that is centrally accessible, ensuring it properly happens is nothing but inter-system testing. 
• Another example can be booking train tickets through PAYTM or any third-party Online Payment application which makes the use of customer IRCTC data. Here the communication of data happens within two systems.
• Another example can be advertising links on one website for another website. Then in this case, if any user clicks on advertising links then you have to get the proper required data of another website and show it to the user on your website.

Advantages of Inter-system Testing

• It helps in ensuring the working of the system in an interoperability environment.
• It avoids future system failure in the case of third-party inter-dependency.
• It verifies the integration of the system's common sources of data/resources.
• Defects can be found before release.

Disadvantages of Inter-System Testing

• It can be costly to test when there is more inter dependability and inter iterations between applications.
• Maintenance may be a problem when both systems are undergoing internal changes.
• Performing inter-system testing may be time-consuming.

Conclusion

Inter-System Testing ensures smooth communication and integration between more than one software applications by verifying the access and sharing of common data. While it secure the future problems and validates system correctly, it can be costly and time bases, making challenges in maintenance. its importance in daily interconnected software environment remains same for ensure the betterment purpose.