Using software evolution to focus architectural recovery

Abstract

Ideally, a software project commences with requirements gathering and specification, reaches its major milestone with system implementation and delivery, and then continues, possibly indefinitely, into an operation and maintenance phase. The software system's architecture is in many ways the linchpin of this process: it is supposed to be an effective reification of the system's technical requirements and to be faithfully reflected in the system's implementation. Furthermore, the architecture is meant to guide system evolution, while also being updated in the process. However, in reality developers frequently deviate from the architecture, causing architectural erosion, a phenomenon in which the initial, "as documented" architecture of an application is (arbitrarily) modified to the point where its key properties no longer hold. Architectural recovery is a process frequently used to cope with architectural erosion whereby the current, "as implemented" architecture of a software system is extracted from the system's implementation. In this paper we propose a light-weight approach to architectural recovery, called Focus, which has three unique facets. First, Focus uses a system's evolution requirements to isolate and incrementally recover only the fragment of the system's architecture affected by the evolution. In this manner, Focus allows engineers to direct their primary attention to the part of the system that is immediately impacted by the desired change; subsequent changes will incrementally uncover additional parts of the system's architecture. Secondly, in addition to software components, which are the usual target of existing recovery approaches, Focus also recovers the key architectural notions of software connector and architectural style. Finally, Focus does not only recover a system's architecture, but may in fact rearchitect the system. We have applied and evaluated Focus in the context of several off-the-shelf applications and architectural styles to date. We discuss its key strengths and point out several open issues that will frame our future work.

A comparative analysis of software architecture recovery techniques

“…Over the span of a decade, we developed, evaluated, and refined a semi-automated software architecture recovery technique, called Focus [17], [32]. We subsequently used Focus to recover the architectures of 18 open-source platforms for scientific computing and processing large datasets [29].…”

Software Architecture Reconstruction: A Process-Oriented Taxonomy

“…Conceptual architecture: This term refers to the architecture that exists in human minds or in the software documentation [134,162]. In the literature, conceptual architecture is also qualified as idealized [60], intended [134,175], as-designed [76,162] or logical [105].…”

“…It is also known as the as-implemented [76,134], as-built [60,162], realized [175] or physical [105] architecture.…”

A Lightweight Sanity Check for Implemented Architectures

“…One approach that does this is the one proposed by Medvidovic [12]. In this approach, an evaluator first extracts the main components of a systems architecture and then maps these components to a notion of the "ideal" architecture for a system.…”