View extraction and view fusion in architectural understanding

When performing architectural analysis on legacy software systems, it is frequently necessary to extract the architecture of the system, because it has not been documented, or because its documentation is out of date. However, architectural information does not exist directly in the artifacts that we can extract. The architecture exists in abstractions; compositions of extracted information. Thus, extracted artifacts must be able to be flexibly aggregated and combined. We call this process "view refinement and fusion". This paper presents a workbench for architectural extraction called Dali, and shows how Dali supports flexible extraction and fusion of architectural information. Its use is described through two extended examples of architectural reconstruction.