Building robust and resilient systems is a major challenge for engineering. To this end, analytical indicators may be useful for managers in making decisions. In this paper, a new analytical construct is presented: the action horizon. This construct is devoted to assisting in the control of a system when an event driving the system to its collapse is detected. This construct is useful for analysing the best moment to start executing a corrective action. In this paper, the action horizon is experimentally evaluated in the predator-prey system and we discuss how it could help with managing power systems.