Abstract : Building large scale systems involves many design decisions, both at specification and implementation levels. This is due to numerous variants in the description of the task to achieve and its execution context as well as in the assembly of software components. We adopt a model-driven perspective, relying on different models and their transformations. We have started to model variability for large scale systems using feature diagrams, a formalism well suited for modeling variability. Our test application domain is video surveillance software platforms, from a software engineering perspective. These are good candidates to put MDE to the test, because of the huge variability in both the surveillance tasks and the video analysis algorithms. Our work was first concentrated on deployment of video-surveillance systems, now we rather work on runtime adaptation too.