1. A method for determining quality of service (QoS) policies based on a mission representation, the method comprising: receiving, by a computing device, a mission representation including a plurality of actions in a mission and temporal and functional associations between the actions, wherein the actions are to be executed using a plurality of computing nodes; generating, by the computing device, a Time Petri Net (TPN) model of the mission based on the mission representation, wherein the TPN model represents the actions in the mission, temporal constraints for the actions, and functional associations between the actions; determining, by the computing device, an importance value and an urgency value associated with each action based on the TPN model, wherein the urgency value is determined based on a derived start time and a slack of the action; and generating, by the computing device, one or more QoS policies based on the importance values and the urgency values of the actions, wherein the QoS policies are applied to the computing nodes within which the actions are executed.