Introduction

Who does integration testing in your organization? Your answer will determine what types of tests should be executed and how they are automated. Is there a separate group, made up of people who are neither developers nor system testers, that tests the application immediately following the build process? In some departments, the developers create their own builds and test the integrated units. In other groups, a specialist—a build master—does some preliminary tests before the application is given to the system test group, who complete the build. Is integration testing really the build master's responsibility?

There is a second question: What is integration testing? This answer can be found by analyzing the answer to the first question. If the answers do not reflect a structured build and test process, the integration testing is a free-for-all ad hoc approach that may or may not be completed effectively. But how much control is needed?

To answer this question, we must recognize that this is one of the most problem-prone areas of development. An effective process supported by a good automated tool is required. Wherever we have consulted, we have seen two chronic problems: First, the build frequently does not install on the system test machines. Second, the fact that unit and integration testing has not been done previously forces the system test team to do tests that development should have already executed.

Integration testing, like unit testing, must be automated because otherwise it will not be done. The minimum automated tool set required for integration testing includes a defect tracking system, a problem reporting system, a capture/playback tool, and a configuration management tool. The tool set must be integrated in the sense that the builds and files in the configuration management (CM) repository can be associated with automated tests in the test repository and with the defects in the defect database.

Why is such tight integration needed? It is necessary because many applications require problem resolution across builds as well as across major and minor production releases. Tools such as Rational Software's ClearCase, ClearQuest, and Robot offer this type of control for integration testing.