Runtime architecture is important because it helps reason about quality attributes such as performance and security. We conducted an on-site field study to help us understand how developers understand object relationships, and what tool features a developer might need to convey their mental model of object relationships.The subject of our study was an experienced, professional programmer. We asked the developer questions to check if he understood which tiers objects belonged to, and whether certain objects were conceptually part of other objects. We also took an initial runtime architecture and refined it to convey his intent. The developer's mental model seemed to agree with the one supported by the current, batch-oriented approach for extracting architectures.This indicates that an interactive tool that allows making an object conceptually part of another, and abstracting away a low-level object would be useful to iteratively refine an initial object model.

We propose an interactive editor which allows developers to refine an initially extracted object graph into a hierarchical graph that matches their mental model of the runtime structure. The developer can expand or collapse selected hierarchies to control the level of visual detail. Such views of the runtime structure can be useful for code modification tasks.