Selecting the assembly sequence and associated automatic assembly stations necessary to assemble a candidate product design is a critical step in the life cycle of a product. We present a method that determines the best sequence and set of stations using cost and performance measures. The method uses a multi-echelon optimization procedure based on simulated annealing. We show how simulated annealing can be used for such problems and present examples in which we determine the optimal assembly sequence for a product in an automated manufacturing environment.