Performance models can help in the design process by locating bottlenecks in the system that may not be visible during the development of the software and for determining capacities. However making models is not a trivial task and its ability to capture performance related detail is a concern. This work introduces an automated method to construct models from traces of a running distributed application. In this model tasks exhibit internal concurrency, specifically asynchronous remote procedure calls and early replies by a server. The trace information is transformed into a layered queuing network (LQN) model where behaviours of tasks are modeled using activity graphs (AGs) with fork and join activities.