Abstract. Design pattern formalization is aimed at encouraging the use of design patterns during the design phase. Many approaches focuses on providing solutions with a graphical notation and complementary text, typically composed by a static and a dynamic definitions. The weak point is the lack of flexibility when customizing the generic solution to the specific context of use. This paper proposes a criterion to motivate design pattern selection and reuse. Designer is supported with a technique for balancing pattern and context forces for selecting among alternative implementations. The provided representation summarizes and organizes relevant information in the classical informal pattern documentation. Key words: Design Patterns, Goal-Oriented Modeling