Long-living software systems are sustainable if they can be cost-efficiently maintained and evolved over their entire life-cycle. The quality of software architectures determines sustainability to a large extent. Scenario-based software architecture evaluation methods can support sustainability analysis, but they are still reluctantly used in practice. They are also not integrated with architecture-level metrics when evaluating implemented systems, which limits their capabilities. Existing literature reviews for architecture evaluation focus on scenario-based methods, but do not provide a critical reflection of the applicability of such methods for sustainability evaluation. Our goal is to measure the sustainability of a software architecture both during early design using scenarios and during evolution using scenarios and metrics, which is highly relevant in practice. We thus provide a systematic literature review assessing scenario-based methods for sustainability support and categorize more than 40 architecture-level metrics according to several design principles. Our review identifies a need for further empirical research, for the integration of existing methods, and for the more efficient use of formal architectural models.

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Sustainability evaluation of software architectures: a systematic review

The idea behind microservices architecture is to develop a single large, complex application as a suite of small, cohesive, independent services. On the other way, monolithic systems get larger over the time, deviating from the intended architecture, and becoming risky and expensive to evolve. This paper describes a technique to identify and define microservices on monolithic enterprise systems. As the major contribution, our evaluation shows that our approach was able to identify relevant candidates to become microservices on a 750 KLOC banking system.

Towards a Technique for Extracting Microservices from Monolithic Enterprise Systems.

Architectural erosion is a recurrent problem faced by software architects. Despite this fact, the process is usually tackled in ad hoc way, without adequate tool support at the architecture level. To address this issue, we describe the preliminary design of a recommendation system whose main purpose is to provide refactoring guidelines for developers and maintainers during the task of reversing an architectural erosion process. The paper formally describes first recommendations proposed in our current research and results of their application in a web-based application.

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Recommending Refactorings to Reverse Software Architecture Erosion

Architecture Consistency (AC) aims to align implemented systems with their intended architectures Several AC approaches and tools have been proposed and empirically evaluated, suggesting favourabl 

/pdf/architecture-consistency-state-of-the-practice-challenges-3tdz2341j0.pdf

Architecture consistency: State of the practice, challenges and requirements

Technical debt and system architecture

In industries such as banking, retail, transportation, and telecommunications, large software systems support numerous work processes and develop over many years. Throughout their evolution, such systems are subject to repeated debugging and feature enhancements. Consequently, they gradually deviate from the intended architecture and deteriorate into unmanageable monoliths. To contend with this, practitioners often rewrite the entire application in a new technology or invest considerable time in documenting the code and training new engineers to work on it. However, for very large systems, such approaches are typically impossible to carry out. As an alternative, researchers have proposed several tools to automatically modularize software that's grown to be inadequate in both quality and scalability. This case study describes the modularization approach that one company adopted to reengineer a monolithic banking application beset with maintenance and complexity problems. In this case study, we describe the modularization approach we adopted to address this situation, as well as certain other benefits we unearthed as a result of this reengineering exercise.

M.K. Iyengar

Papers

Modularization of a Large-Scale Business Application: A Case Study