Testery enables you to set the number of parallel tests to optimize how your test runs are queued up or throttle test runs so they don't overwhelm the system-under-test.
When editing the scheduled test run, select
Show Advanced Options and specify the Number of Parallel tests. Be sure to set this number to less than the total available for your account if you'd like to be able to have multiple test runs running at the same time.
You can also set the number of parallel tests when running an ad hoc test run. To do this, when creating the test run, expand
Show Advanced Options and specify the desired number of parallel tests.