ABSTRACT The goal of this study is to propose a decision model for supporting the choice of the best-agile model, based on the Flexible and Interactive Tradeoff (FITradeoff) method. This study provides the definition of an extensive set of 38 measurable criteria that were considered for evaluation of the most popular agile process models used in small and medium-scale enterprises. To illustrate the application of the model, we applied it to a set of alternatives that includes DSDM, SCRUM, XP2 and Crystal and an experienced project manager acted as our decision maker during the interactive elicitation process of the FITradeoff. The results show that the FITradeoff is very valuable for this class of problem because of its strong mathematical foundation and the possibility of combining two different ways for modeling the preferences of decision makers, which makes the process cognitively easier than other multi-criteria methods and increase the confidence on the results. Although our study focuses on the context of small and medium-scale companies for software development, the approach can be used to other types of environments, including distributed software development and large enterprises.