The Main sequence initiates the tests on a UUT. The process model defines what is constant about the testing process, and Main sequences define the unique steps for the different types of tests to run. When you create a new sequence file, TestStand automatically inserts a Main sequence in the file. You must name each Main sequence MainSequence.

The process model invokes the Main sequence as part of the overall testing process. TestStand uses the station process model file to determine which process model file to use with the Main sequence unless the sequence file specifies a different process model file and you enabled the Allow Other Models option in the Station Options dialog box to allow sequence files to override the station model setting.

After TestStand identifies the process model to use with the Main sequence, the file that contains the Main sequence becomes a client sequence file of the process model.