A new approach for tackling uncertainties in preference elicitation and predictive modeling of complex MCDA/MAUT problems and its application to water infrastructure planning in Switzerland will be presented. To this end, a two-step procedure for preference elicitation is combined with uncertainty and global sensitivity analyses (UA, GSA). This covers uncertainty of the preference components (marginal value and utility functions, hierarchical aggregation functions, aggregation parameters) and the attribute predictions. Context uncertainties about future socio-economic developments are captured by combining MAUT with scenario planning. We perform a global sensitivity analysis (GSA) to assess the contribution of single uncertain preference parameters to the uncertainty of the ranking of alternatives. This is done taking into account the implications of five different GSA designs regarding the choice of the feasible sample space. We will show the usefulness of UA and GSA to explore the importance and contribution of often ignored uncertainties and to focus on those crucial for discriminating alternatives. Based on these results, we will furthermore demonstrate that a priori assumptions such as linear value functions or additive aggregation can result in misleading recommendations, unless thoroughly checked during preference elicitation and modeling. This work has been recently published (Scholten et al. 2015). We now strive to adapt this work such that GSA can be used to inform the decision analysis process about the most sensitive parameters before detailed preference assessment and attribute prediction is undertaken. We will present an outlook on work in progress and some challenges faced in further developing the framework. This framework will be beneficial for water infrastructure planning and other complex planning situations, as it allows to identify which components of the overall MCDA it is worth to focus efforts on, and under which conditions. Reference: Scholten, L., Reichert, P., Schuwirth, N., Lienert, J., 2015. Tackling uncertainty in multi-criteria decision analysis- An application to water supply infrastructure planning. European Journal of Operational Research 242(1) 243-260.