A major issue in the characterization of photovoltaic modules is the limitation of the homogenously irradiated area provided by the available sun simulators. Therefore the Stepwise Measurement Procedure for the Characterization of Large-area PV Modules (SMP) was developed recently. This concept enables the characterization of modules with aperture areas larger than the area provided by a given sun simulator. In previous investigations the procedure demonstrated good applicability and high accuracy. In a real application environment, however, conditions like temperature and stray light might influence the measurement. Also, particular variations within a module like e.g. defective cells may lead to higher uncertainties for the results of the SMP. Therefore, an investigation of the impact of these factors on the accuracy of the procedure is performed. The results show that the impact of most factors can be minimized and even eliminated. Therefore, recommendations for the practical application are given. (C) 2016 The Authors. Published by Elsevier Ltd.