Measuring Architecture Sustainability

It´s difficult to express a software architecture´s sustainability in a single metric: relevant information is spread across requirements, architecture design documents, technology choices, source code, system context, and software architects´ implicit knowledge. Many aspects influence economic sustainability, including design decisions facilitating evolutionary changes, adherence to good modularization practices, and technology choices. An approach that focuses on a single artifact or perspective is likely to neglect important factors. ABB Corporate Research is tracking the architecture sustainability of a large-scale industrial control system currently under development. A former version of the system grew to several million LOC and suffered from architecture erosion and high maintenance costs. A multiperspective approach called Morphosis will help avoid such a situation in the future by focusing on requirements, architecture design, and source code. It includes evolution scenario analysis, scoring of technology choices, architecture compliance checks, and tracking of architecture-level code metrics.