The article discusses the importance of integration testing in software development, especially in large projects like the Department of Defense's Y2K testing. Integration testing, which checks how different parts of a software work together, is crucial and time-consuming. To address this, the DoD started a project focusing on end-to-end integration testing. This approach aims to test the entire system as a whole, rather than just individual parts. The key finding is that in complex projects, like the DoD's Y2K testing, integration testing is more resource-intensive and critical than module testing.