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.