This paper presents a formalism called Time Interval Petri Nets (TIPNs) and shows their efficacy for model-based envisionment of real-time concurrent interacting processes with temporal constraints. The TIPN formalism is developed by extending Petri Nets to Time Interval Petri Nets. The process of TIPN construction from a state-process domain model is described. Experimental results in the domain of ship crisis decision-making show five orders of magnitude speed up over a first-principals numerical physical system simulator in a complex domain. An advantage of TIPNs is a graphical network representation that facilitates model construction, refinement, and comprehension. Keywords: Limited Rationality, Real-time Decision Making, Petri Nets, Intelligent Systems, Knowledge Acquisition, Temporal Reasoning, Envisionment-based Control Policies.