How to Implement Software Integration Testing

What is Software Integration Testing?

Software integration testing is a type of testing where individual software modules are integrated together and tested as a unit. The goal is to ensure that different modules within the platform work together and that there’s a seamless interaction between them. It is an important part of the software development life cycle as it helps teams catch defects before they impact production. 

The result is a higher-quality product with fewer system failures. Overall, integration testing is about ensuring a seamless and user-friendly experience with the system. Let’s dig deeper into integration testing and discuss the value it provides organizations.

Types of Integration Testing

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Developers perform two levels of integration testing in software testing. The two methods used are: 

  • Component Integration Testing: This type of evaluation focuses on verifying interactions between two or more units of code (methods/function). 
  • System Integration Testing: With this approach, developers evaluate interactions between two or more systems. The system that needs integration can be either internal or external. External systems are typically exposed via an Application Programming Interface (API).

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Value of Software Integration Testing

Modern software consists of several moving parts. An issue in one module could negatively impact the entire system. Validating that they all work together seamlessly is essential to delivering a product that delights the customer. Additional benefits include:

  • Better Quality Product: Performing integration testing in software integration helps teams catch defects before deploying the application to customers and verifies that the software will have the highest-quality performance when introduced to users. As a result, the system provides a seamless and user-friendly experience, increasing customer satisfaction.
  • Fewer System Failures: Integration testing enables teams to fix issues that may cause system failures. Delivering a reliable product helps increase customer confidence in using the systems.
  • Early Bug Detection: Testing your integrations helps expose malfunctions or defects between two or more integrated features early on. This ensures that teams are correcting all issues before the software goes to market 
  • Saves Time and Money: Fixing a bug after production deployment is expensive and time-consuming. It requires resources to deal with the problems, which takes that person away from other value-added tasks. Not only that, the company must pay for the additional hours the employee spends working to fix issues in the tested system.

Integration testing requires many moving parts and a significant setup. Teams will need to prioritize and plan their approach carefully to maximize their efforts.

4 Common Approaches to Integration and Testing Software

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Given the complexity of modern systems, relying on one method of integration testing could be detrimental. The team could miss defects that would only be found through more invasive validation. There are several approaches a team could use. Each approach lets the team evaluate the system from different vantage points. 

Here are the most common approaches to integration testing in software engineering. 

Big Bang Integration Testing

Big Bang Testing is an approach in which all the components or integrated units are combined and tested as a unit and relies on all components being ready for validation at once. If one component fails, all test cases fail. 

This approach is suitable for small systems. However, it relies on all modules being ready before validation begins. As a result, teams will experience delays while waiting on all items to be completed. Also, this type of strategy is risky in that modules aren’t tested in isolation. The team could accumulate a lot of bugs this way by waiting until all modules are completed.

Bottom-Up Integration Approach to Testing

This verification strategy evaluates the lower-level modules first. These tested modules are then further used to test higher-level modules. The process continues until all modules are tested. The advantage of this form of integration testing in software engineering is that no stubs are required.  

Top-Down Integration Testing

In this approach, the team evaluates higher-level modules first. These tested modules are then used to test the lower-level components. The process continues until all modules are tested. The main benefit here is that few or no drivers are needed. However, it does require many stubs.

Mixed Integration Testing (Sandwich Testing)

This method of validation is an approach where teams evaluate top-level modules and lower-level modules at the same time. 

Here, lower modules are integrated with top modules and tested as a system. It is a combination of top-down and bottom-up approaches. This approach is beneficial for large projects that have sub-projects. It is not ideal for small systems with significant interdependence between units.

Tips and Tricks for Implementing Software Integration Testing 

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Implementing a successful software integration strategy is critical to your product’s success. Developing an approach to testing is the first step in delivering quality software. These best practices will get you started in the right direction. 

Understand Test Strategy and Test Environment

The first step is to ensure you have an appropriate test environment in order for the team to validate the system without impacting production. Next, evaluate which method of software integration testing you will perform. You may choose one or a combination of methods.

Plan For Resources

Determine what resources you need for testing. Confirm that you have testers in-house or if you will need to hire an external team

Prepare and Communicate the Test Plan

Once you decide on a strategy, prepare the test plan. The plan outlines:

  • Data required for the test
  • Test cases
  • Which modules will be tested
  • Test scripts
  • How data will be analyzed

With a successful test plan, the team has a clear understanding of the test objectives and the desired outcome. 

Prioritize Modules

Prioritize in which order you plan to test each module. Prioritization differs for each team. The important thing is to prioritize them in a manner that aligns with your test strategy and company goals.

Test Carefully

This step is when actual testing happens. The tester executes each test and analyzes the results to identify defects. Integration testing is a cyclical process whereby the tester continues to retest until all defects are resolved.

Many teams use a DevOps approach to testing. This approach incorporates testing into the delivery and deployment process. That way, testing is automated which saves time and enables the team to rerun tests as often as necessary. 

Successful Integration Testing With a Trusted Advisor

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KMS Technology has proven experience in software integration testing. Our experts can evaluate your current systems and layout a strategy for your integration testing plan. With proven success in automated testing and QA testing, we can help fill in internal gaps/knowledge when conducting testing. At KMS we build the highest quality software that exceeds customer expectations. 

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