What's your go-to method for testing system integration?

1 Choose a test strategy

Before you start testing your system integration, you need to decide on a test strategy that defines the overall approach, scope, and level of testing. This strategy should be aligned with your system's architecture, functionality, and quality attributes, as well as your project's constraints, risks, and stakeholders' expectations. Common strategies for system integration include the Big Bang approach (testing the entire system as a whole), Incremental testing (testing the system in increments), Top-down (testing from the top level to the lower levels), and Bottom-up (testing from the lower levels to the top level). Each strategy has its own advantages and disadvantages, such as simplicity, reliability, or performance. It is important to choose the right strategy for your project based on these factors.

2 Define test objectives

Once you decide on a test strategy, you need to define test objectives that clarify what you want to accomplish and measure with your system integration testing. These objectives should be SMART: clear, specific, measurable, achievable, relevant, and time-bound. Additionally, they should be in line with the system's requirements, design, and quality attributes. Some examples of test objectives include confirming that the system's components interact correctly and consistently with each other and with external systems or interfaces; validating that the system's functionality, performance, security, usability, reliability, and availability meet the criteria and standards; detecting and fixing any defects, errors, or inconsistencies in the system's integration or configuration; and assessing the system's readiness for deployment, operation, or maintenance.

3 Design test cases

In order to achieve your test objectives, you must design test cases that detail the inputs, outputs, conditions, and expected results of each test scenario. The test cases should be based on the system's requirements, design, and quality attributes and must cover all relevant aspects of the system's integration. This includes data flow and exchange between components or systems, interface compatibility and compliance, functional integration and interoperability, non-functional integration and performance, and integration error handling and recovery.

4 Execute test cases

After you design your test cases, it’s important to execute them according to your test plan and schedule. Test execution involves setting up the test environment, preparing the test data, running the test cases, and recording the test results. Whenever possible and feasible, automated tools and scripts should be used to run and monitor the test cases. Test logs and reports should be used to track and document the test progress, outcomes, and issues. Additionally, test metrics and indicators should be used to measure and evaluate the test effectiveness, efficiency, and quality. Finally, reviews and feedback should be used to improve and optimize the test process and performance.

5 Analyze test results

After executing your test cases, you need to analyze the test results to determine the status and quality of your system's integration. Test analysis involves comparing the actual results with the expected results, as well as identifying and classifying any deviations. This should be followed by prioritizing and assigning the issues for correction, retesting, or mitigation. It is also important to report and communicate the test results and issues to the relevant stakeholders.

6 Follow up test activities

After you analyze your test results, you need to follow up the test activities to ensure that your system's integration is complete, correct, and compliant. This can include retesting the system's integration after fixing or modifying components or configuration, regression testing the system's functionality and performance after integrating new or changed components or systems, and acceptance testing the system's integration with end-users or customers to confirm that it meets their expectations and needs. Additionally, you should document and archive the test artifacts, such as test cases, results, reports, logs, metrics, and issues.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?