Human performance can seriously degrade under demanding tasks. To improve performance, agents can reason about the current state of the human, and give the most appropriate and effective support. To enable this, the agent needs a work pressure model, which should be valid, as the agent might otherwise give inappropriate advice and even worsen performance. This paper concerns the validation of an existing work pressure model. First, human experiments have been designed and conducted, whereby measurements related to the model have been performed. Next, this data has been used to obtain appropriate parameter settings for the work pressure model, describing the specific subject. Finally, the work pressure model, with the tailored parameter settings, has been used to predict human behavior to investigate predictive capabilities of the model. The results have been analyzed using formal verification.