Software architecture modeling and representation are a main phase of the development process of complex systems. In fact, software architecture representation provides many advantages during all phases of software life cycle. Nevertheless, for many systems, like legacy or eroded ones, there is no available representation of their architectures. In order to benefit from this representation, we propose an approach called ROMANTIC which focuses on extracting a component-based architecture of an existing object-oriented system. This approach considers this problem as a balancing problem of competing constraints which aims to select the best solution among all the possible architectures. Consequently, we present in this paper the identified constraints of this problem and its formulation as a search-based problem.