The following technical report is available from http://aib.informatik.rwth-aachen.de: Introducing Timers to pi-Calculus Kamal Barakat AIB 2011-18 Modeling systems of concurrent processes can be improved if the concept of time is represented in the model. Pi-calculus is a suitable process algebra for modeling communicating processes that exchange messages and is able to model mobility through dynamic channel setup and through privatizing names using restriction. Therefore, it is beneficial to extend pi-calculus to embrace the notion of time.