Researchers have defined a number of process modeling methods and have developed in-roads to process-centered environments that support process modeling and project control. However, there is little research that incorporates variability of the human condition into process modeling. The negative effects of numerous variables on the quality of human situation assessment and decision making can be as detrimental to expected results as any catastrophic failure. The research documented in this paper proposes a model for Situation Assessment, and derives a taxonomy of individual, task, environmental, and organizational attributes that can affect situation assessment and decision making.' The model and attributes are integrated with a state-based process modeling paradigm. The MultiGraph Architecture, Vanderbilt University's model-integrated computing environment, was used quickly and cost-effectively to generate a graphical process modeling environment that accounts for situation assessment and decision making.