Test case executors are the intended users of the DDTT at this level and is a procedural interface. DDTT test cases are contained in flat text files called Script Files. Typically, each script file contains one test case, although a test case could span multiple files by utilizing the DDTT's script file's include capability.

To start a test case contained within a file named TEST01.SCR, type DDTT TEST01.SCR from an OS/2 command prompt.

Operator prompts are displayed in separate windows, one window for each test thread. Any resulting logs are written to the file names specified on the @THREAD commands in the test script file.

At the Test-Case Execution level, the DDTT requires limited knowledge of OS/2 (for example, how to start and stop command files, and any device-specific knowledge required by the test-case grammar file.

DDTT scripted test cases are repeatable. When a test case is defined and contained within a Test-Case Script File, the execution and subsequent re-executions of the test case always execute functions within a thread in the same order. Although intra-thread operations occur in the same order, there is no guarantee that inter-thread operations will always occur in the same order. Use the DDTT's shared file logging to determine test-case execution order in multiple thread test cases.