This project is about human–computer interaction, consisting of two parts. Thefirst part is to analyze human behavior through the observation of machine/systembehavior – solely through network traffic. By observing this in a multi user system– what they do and when they do it, this thesis aims to see if distinct features ofthe population can be found and later reenacted. This will be achieved throughobserving network traffic, gathering it in a structured way and characterizing it.Humans and their computer workstations are the principal factors in making thetraffic that is going to be measured.The second part is to simulate the behavior and network traffic observed withvirtual users – programs which behave similarly to their real counterparts. This isdone with scripting, and results in a configurable tool which can simulate humanbehavior as seen from the network. Humans are thus eliminated in favor of computersimulated virtual users. The virtual users will try to generate network traffic withthe same type, amount, and characteristics as observed in the first part, in asimulation with a hitherto unprecedented level of realism. Ideally, if this is repeated,it will form an idempotent loop ending up still looking like the original system withreal users.