Release planning is a cornerstone problem in incremental software development. It deals with the assignment of requirements to sequence of releases in order to maximize profit, minimize the delay of feedback and return of investment in such a way that dependency and resource constraints are met. Release planning decisions are required at an early stage in the development cycle, when uncertainty is unavoidable in the project estimates. Recently, there are some works concerning the use of fuzzy theory to address issues concerning the uncertainty in the release planning problem: fuzzy effort constraints and fuzzy dependency constraints. In this paper, we study the application of fuzzy theory to handle the uncertainty concerning dependency constraints from a holistic perspective, i.e. the whole set of fuzzy dependency constraints is considered as a fuzzy graph. The satisfaction of dependency constraints in a solution plan is measured by the distance between this plan and an ideal plan (in terms of the dependency constraints). The distance is materialized as the distance between two fuzzy graphs. This is considered to be an essential support for the actual decision-making. All the concepts and the complete approach are illustrated by a case study example.