The Failure Steps pane is used to define any project steps that should be executed when any step in the build fails.  Multiple failure steps can be defined, and conditional build rules can be used to only build some failure steps in certain situations.  For instance, a set of steps to undo a checkout action could be configured to build only if the step that failed was the step to perform a checkout.  Information about a failed step is available in the system macros FAIL_STEP_NAME, FAIL_STEP_STATUS, and FAIL_STEP_OUTPUT.  If a failure step fails and is not marked to ignore failure, the build stops without processing any more failure steps.