A Graph Pattern Matching Approach to Software Architecture Recovery **This work was funded by IBM Canada Ltd. Laboratory - Center for Advanced Studies (Toronto) and the National Research Council of Canada.

This paper presents a technique for recovering the high level design of legacy software systems based on pattern matching and user defined architectural patterns. Architectural patterns are represented using a description language that is mapped to an attributed relational graph and allows to specify the legacy system components and their data and control flow interactions. Such pattern descriptions are viewed as queries that are applied against an entity-relation graph that represents information extracted from the source code of the software system. A multi-phase branch and bound search algorithm with a forward checking mechanism controls the matching process of the two graphs by which, the query is satisfied and its variables are instantiated. An association based scoring mechanism is used to rank the alternative results generated by the matching process. Experimental results of applying the technique on the Xfig system are also presented.