<p>This paper presents a new Multicriteria Group Decision-Making (MCGDM) process with partial preference information, based on Flexible and Interactive Tradeoff (FITradeoff). With a focused, structured approach for aggregating decision-makers’ (DMs’) preferences within a flexible decision process, a FITradeoff-GDSS (Group Decision Support System) is developed as a practical decision tool for aiding group decision situations with multiple criteria. Different preference structures of DMs are analyzed in such a way that DMs do not need to provide complete information. This GDSS requires less cognitive effort from DMs. The preference modeling process can use different perspectives, with separate or simultaneous elicitation processes. Both processes can provide a deep analysis of the DMs’ results and concentrate the analysis on the potential optimal alternatives, with the information of their individual rankings for each DM. In both cases, the FITradeoff-GDSS provides, at each step of the process, several visualizations for aiding the analysis of partial results. The analysis of these partial results makes it possible to reach a final agreement without going further in the elicitation process. In both processes, the FITradeoff-GDSS offers analytical aggregation tools to find a compromise solution for the group, considering both cardinal and ordinal aggregation approaches. The new process is demonstrated based on an application for selecting a package to improve the safety of oil tankers. This paper goes a step further in the literature of Group Decision analysis to the field of group decision, using a flexible and interactive elicitation process that combines both decomposition and holistic evaluation.</p>