Abstract
This paper presents a computational model of the dynamics of a human's functional state in relation to task performance and environment. It can be used in intelligent systems that support humans in demanding circumstances. The model takes task demand and situational aspects as input and calculates internal factors related to human functioning, such as the experienced pressure, exhaustion, and motivation, and how they affect performance. Simulation experiments under different parameter settings pointed out that the model is able to produce realistic behavior of humans with different types of personalities. Moreover, by a mathematical analysis the equilibria of the model have been determined, and by automated checking a number of expected properties of the model have been confirmed. In addition to this "internal" validation of the model, an experiment has been designed for the purpose of external validation, addressing the estimation of aspects of the human process that are relevant for its practical application. Output from the experiment, like information about personality characteristics and performance quality, has been used to perform estimation of the parameters of the model. By the parameter estimation, a set of parameter values has been identified by which an adequate representation of a person's functional state when performing a task is achieved.
