Business Process modeling enables an organization to manage their business operations in an effective way. Given that there are too many process models in an organization, management of these models requires maintaining large repositories of process models as well as automatic techniques for managing process repositories. The features of a process repository are classified into four types, evaluation, comparison, management and presentation. Where evaluation covers the analysis of quality, correctness and performance of process models, comparison covers similarity between models and pattern based analysis, management describes how to control extensions, individualization and reference based completion of the repository, and presentation of process models relates to useful generalization of processes and secondary notations, such as size, and color, etc. Among these, we are interested in comparison process models and querying repository for finding appropriate process models.