Embodiments provide a scheduler for scheduling test times of a plurality of tester software environments for an automatic test equipment. The scheduler is configured to automatically assign test times to the plurality of tester software environments, to acquire test instructions from a tester software environment of the plurality of tester software environments to which a current test time is assigned, to control the automatic test equipment to perform a test according to the test instructions in order to obtain test results, and to provide the test results to the tester software environment of the plurality of tester software environments to which the current test time is assigned.