The present disclosure discloses method and a critical event managing system for managing time-critical events associated with critical devices. The critical event managing system identifies time-critical events from plurality of events based on predetermined factors related to the plurality of events. The plurality of events is determined from first procedural sequences identified from procedural narration by a practitioner and stored protocol manual. At least one of missed and incorrect events are determined based on comparison between reference and observed values associated with critical devices. A revised execution plan is provided iteratively based on historical data, data provided by practitioner, first procedural sequences, and metadata associated with plurality of parameters. The missed and incorrect events are executed as second procedural sequences based on revised execution plan, thereafter, outcome from execution of first procedural sequences and second procedural sequences is combined in order to manage time-critical events associated with critical devices.