System Integration Testing (SIT) is a crucial aspect of the software testing life cycle, where the overall system is tested, ensuring seamless interaction and functionality in disparate parts. The development team conducts SIT to ensure that the different components are integrated and work together correctly as a system. SIT can involve the testing of software, systems, or networks. One simple example can be NetSuite-Shopify integration, where the backend is Oracle NetSuite and the front end is Shopify. These systems are integrated where NetSuite keeps track of inventory and Shopify displays the exact inventory to customers online. This comprehensive guide offers an overview of integrated system testing, including its purpose, process, cha- llenges and best practices.

What is System Integration Testing?

System integration testing (SIT) is a type of software testing, carried out to perform the overall testing of a system consisting of various integrated components. SIT is a QA (Quality Assurance) process ensuring the compatibility of two or more systems. It helps developers ensure that the integrated systems are working together correctly and that interactions between them are appropriate and safe. It involves testing of software, systems, or networks to check the system’s performance, integrity, and compatibility.

What are Different System Integration Testing Techniques?

System integration testing, also referred to as Incremental testing, is a process that uses dummy programs and drivers to test the interactions between components of a system. Here are some different system integration testing techniques:

Bottom-Up Integration Testing:

This testing starts at the lowest level of the module in the tech stack’s architecture, where the control flows towards the top of the hierarchy. This test is done during the early phase of development making it for fixing bugs straight away with minimal identification and troubleshooting time.

Top Down Integration Testing:

In top down SIT, the testing starts from the top module, where the control flows from top to the bottom through control flow of architecture structure.

Sandwich Testing:

Sandwich testing, also known as hybrid integration testing combines both top down and bottom up SIT testing. In this approach testing is done in both directions higher-level modules (upwards) and lower-level modules (downwards). The downside of sandwich testing is that it is complex, where the process begins at the middle layer and combines two different integration testing approaches.

Big Bang Integration Testing:

It is a form of non-incremental type of integrated system testing, which is performed when all the modules are assembled into a complete system. All the modules are integrated together and tested as a single unit, suitable for smaller systems.

Who Performs System Integration Testing?

Some of the key stakeholders involved in performing SIT are as follows:

Test Manager / Test Lead

As a part of the development team, they outline the scope, objectives, approach, and schedule for SIT, deciding who can perform system integration testing based on their roles.

Integration Testers

A tester develops a detailed case study highlighting the progress of system integration testing and verifies whether the integrated components are functioning correctly as a software system. He also identifies and logs defect reports for developers, ensuring timely resolution.

System Architects and Developers

They collaborate with the testing team to understand various integration requirements and designs. They also provide the necessary support to set up the integrated testing environment.

Business Analysts

They also collaborate with the testers, ensuring the integrated system meets their business requirements. They participate in various testing processes, reviewing and validating the system integration tests.

Common Challenges in SIT

System integration testing (SIT) involves testing a system that consists of multiple subsystem components, such as hardware, software, or hardware with embedded software. Some challenges of SIT include:

●Managing Diverse Components: Integrated system testing often involves a mix of new and legacy systems, custom code, and third-party applications. Ensuring compatibility and smooth data flow across these diverse elements can be a challenge.

●Ensuring Comprehensive Test Coverage: Creating test cases that cover all possible interactions and edge cases between integrated systems can be time-consuming and complex.

●Handling Dependencies: Integration testing often involves dealing with complex dependencies between systems. Delays or bugs in one system can cause cascading issues throughout the integration.

●Replicating Real-World Scenarios: Simulating real-world usage patterns and data volumes during testing can be difficult, potentially leading to integration issues that only surface in production.

●Coordinating Testing Schedules: Scheduling and coordinating testing efforts across multiple teams working on different systems can be a logistical challenge.

Conclusion

In conclusion, System Integration Testing is a necessary phase of software development. It helps the team in ensuring that all components of the system are seamlessly working together and efficiently. Here, careful study and documentation of the test are done to ensure that the software is working as intended, ultimately, contributing to the success of the software development and end-user satisfaction. Opkey is a tool that can be used for seamless integrated system testing tests, supporting automation for web, mobile, desktop, and API tests all in one place.