The software development process involves activities that may be modeled as optimization problems. This context may present aspects of uncertain nature, which influence their resolution. One of such problems is the software requirements selection, where factors such as cost of implementation and requirements’ importance must be considered. These aspects can be represented in an uncertain way, then, it is necessary to consider this ambiguity in solving the problem. The model applied gives the rate of possibility for each configuration of cost and importance. The method is applied on several cost and importance configurations, and taken as a whole the resulting information helps on the project planning, as it shows the level of certainty of each situation. Experiments with simulated data are performed to show the application of the approach in the selection of requirements. Results show the efficacy of the approach in small and medium-size instances. Keywords: Software engineering. Optimization. Software requirements