We describe the change situation and the strategic management problems of the academic libraries in the actual context. Then, we define these organizations with complexity paradigm and system thinking. We describe organizational approach as able to response to our strategic management problematic. We present as part of a PhD work the academic models build with constructivist methodology. These models are concerned with services tools of libraries. The main findings concern our contribution to academic libraries modelization and difficulties met in studiyng libraries through a constructivist methodology.