A Lightweight Architecture Analysis of a Monolithic Messaging Gateway

Background: The Enterprise Messaging Gateway (EMG) from Infoflex Connect (ICAB) is a monolithic system used to deliver mobile text messages (SMS) world-wide. The companies using it have diverse requirements on both functionality and quality attributes and would thus benefit from more versatile customizations, e.g. regarding authorization and data replication. Objective: ICAB needed help in assessing the current architecture of EMG in order to find candidates for architectural changes as well as fulfilling the needs of variability in meeting the wide range of customer requirements. Method: We analysed EMG using a lightweight version of ATAM (Architectural Trade-off Analysis Method) to get a better understanding of how different architectural decisions would affect the trade-offs between the quality requirements from the identified stakeholders. Result: Using the results of this structured approach, it was easy for ICAB to identify the functionality that needed to be improved. It also became clear that the selected component should be converted into a set of microservices, each one optimized for a specific set of customers. Limitation: The stakeholder requirements were gathered intermittently during a long period of continuous engagement, but there is a chance some of their requirements were still not communicated to us. Conclusion: Even though this ATAM study was performed internally at ICAB without direct involvement from any external stakeholders, documenting elicited quality attribute requirements and relating them to the EMG architecture provided new, unexpected, and valuable understandings of the system with a rather small effort.