A challenge of componentizing legacy applications is to extract behavior specification of suggested components. It is desirable to preserve a relation between the original structure of the source code of a component and the extracted specification; in particular, this is important for both user comprehension and for interpretation of results of any further formal verification. Even though the reverse engineering techniques providing behavior specification have already been applied on object oriented software and components, none of them targets the interplay of both the externally and internally triggered activities on the component’s provided and required interfaces from a single perspective. This paper targets the problem in the scope of Behavior Protocols and components given as a set of Java classes accompanied with information on component boundaries. To demonstrate viability of the proposed approach, this technique has been partially applied in tractor tool for the SOFA compone...