In this work, a two-dimensional model is used to analyze the main and interaction effects of five design factors, at three levels in a polymer electrolyte membrane (PEM) fuel cell. The model used in this study is a detailed two-dimensional steady-state model, solved using a finite element partial differential equation solver. The factors considered are channel width, shoulder width, gas distribution electrode (GDE) thickness, GDE conductivity and GDE porosity. A full factorial design is used to minimize statistical errors and study interactions accurately. The model used is a two-dimensional, across-the-channel model. The model is run at both the inlet and exit concentrations for fuel and oxidant, allowing the study of interaction effects over a range of operating conditions. The analysis is conducted for operating potentials of 0.7 and 0.6 V and a range of current densities. The strongest interaction effects are found to exist between channel size and GDE conductivity, while the weakest interaction effects are between GDE thickness and GDE porosity. (c) 2005 Elsevier B.V. All rights reserved.