The research project SESAM (Software Engineering Simulation by Animated Models) aims at providing a training environment for future project managers. The basic idea is to create a model of the software development process that can be interpreted by a simulator. The student using the simulator can control the simulated project interactively, leading it more or less successfully. In this paper, the simulation system is presented. Then, a new simulation model, the QA (Quality Assurance) model, is introduced. Discussion focuses on the metrics system used. The QA model covers all activities of software development, from requirements specification to product delivery. It especially emphasises the effects of quality assurance activities. Finally, simulation results obtained by executing the model are presented and discussed.