Abstract
The purpose of this article is to clarify the theoretical base necessary for the design of a computer-based simulation of temporal reasoning. Simulation allows a better understanding of phenomena that appear in working situations and, even, understanding and preventing some human errors. In order to illustrate theoretical concepts, we will provide examples of a situation in which the dynamic character of the evolution, the critical character of the planning and of the synchronization force temporal reasoning. This situation will be that of anaesthesia.