Versioning of Web Services for the Swedish Public Sector’s secure electronic mail service Mina meddelanden

Abstract: Mina meddelanden (English: My Messages) is a secure electronic mail service provided by seven Swedish public authorities, which may be used by the Swedish population to electronically receive mail from the public sector. The IT infrastructure of this mail service is primarily developed and maintained by the Swedish Tax Agency. It is built on Web Services and the principles of Service-Oriented Architecture (SOA). This allows external stakeholders to connect to the system as subsystems: Senders, Postal Services or Mailbox Operators, each designed to either send, mediate or receive mail using Web Services. Used in this way, Web Services allow for a loosely coupled system, however, system upgrades must be deployed in an orderly fashion so as to prevent breakdowns. The main research areas of this literature review, conducted with an iterative search process, include versioning of Web Services, SOA strategies, design patterns and frameworks. Based on the findings of this research, two theoretical approaches are suggested for Mina meddelanden: (i) a gradual change between two strictly controlled versions with a unified repository to store relevant Web service artifacts and documentations, and (ii) more generally to implement an integration platform that includes a service bus to mediate messages to the most suitable version. Mina meddelanden is a government project, and there are strict IT regulations and directives that must be followed. Therefore, the first approach is the most suitable at the time of writing, since there is already a working version of the system that follows these rules. Future implementation of an integration platform requires further study to ensure legal requirements are met.