The safety analysis of a system is a classical field of engineering, with its well-known processes and tools (e.g. fault trees, event trees, reliability block diagrams or a combination among them). Nevertheless, the increasing complexity of systems has to be handled with appropriate approaches and tools: for example the so called Model-Based Safety Assessment approach. In this publication, we present the modelling and assessment of an insulin pump system. Also called “artificial pancreas”, this system is a medical device and a typical example of a cyber-physical system. It contributes to reduce the constraints of diabetic patients caused by their illness. The system is composed of three main parts in close loop. The safety assessment of this system has to be finely analyzed since failures may result in severe harms to the patient. We use the AltaRica 3.0 modeling language, which is such a solution of the Model-Based Safety Assessment approach, to realize the safety assessment of the Insulin Pump System.