Detecting errors during development is far less costly than detecting them in production — the later a bug is found, the harder it is to identify, and the more expensive it becomes to correct. However, manually testing and retesting your code throughout the development process consumes an increasing amount of time and effort as the program becomes more complete, and more complex. To address this challenge, SAP Web Application Server 6.40 introduces the ABAP Unit test tool, which allows you to run automated, unattended, repeatable tests, so you can concentrate on coding rather than on running the tests. This article shows you how to use the tool to produce higher-quality code in less time and with less effort.