As embedded systems need more and more computing power, many products require hardware platforms based on multiple processors. In case of real-time constrained systems, the use of scheduling analysis tools is mandatory to validate the design choices, and to better use the processing capacity of the system. To this end, this paper presents the extension of the scheduling analysis tool Cheddar to deal with multi-processor schedul- ing. In a Model Driven Engineering approach, useful infor- mation about the scheduling of the application is extracted from a model expressed with an architectural language called AADL. We also define how the AADL model must be writen to express the standard policies for the multi-processor scheduling.