Distributed nature of web service computing imposes new challenges on software maintenance community for localizing different software features and maintaining proper quality of service as the services change over time. In this paper, we propose a new approach for identifying the implementation of web service features in a service oriented architecture (SOA) by mining dynamic call trees that are collected from distributed execution traces. The proposed approach addresses the complexities of SOA-based systems that arise from: features whose locations may change due to changing of input parameters; execution traces that are scattered throughout different service provider platforms; and trace files that contain interleaving of execution traces related to different concurrent service users. In this approach, we execute different groups of feature-specific scenarios and mine the resulting dynamic call trees to spot paths in the code of a service feature, which correspond to a specific user input and system state. This allows us to focus on a the implementation of a specific feature in a distributed SOA-based system for different maintenance tasks such as bug localization, structure evaluation, and performance analysis. We define a set of metrics to assess structural properties of a SOA-based system. The effectiveness and applicability of our approach is demonstrated through a case study consisting of two service-oriented banking systems.