A new programming model for enterprise software : Allowing for rapid adaption and supporting maintainability at scale

Abstract: Companies are under constant pressure to adapt and improve their processes to staycompetitive. Since most of their processes are handled by software, it also needs toconstantly change. Those improvements and changes add up over time and increase thecomplexity of the system, which in turn prevents the company from further adaption.In order to change and improve existing business processes and their implementation withinsoftware, several stakeholders have to go through a long process. Current IT methodologies arenot suitable for such a dynamic environment. The analysis of this change process shows thatfour software characteristics are important to speed it up. They are: transparency, adaptability,testability and reparability. Transparency refers to the users capability to understand what thesystem is doing, where and why. Adaptability is a mainly technical characteristic that indicatesthe capability of the system to evolve or change. Testability allows automated testing andvalidation for correctness without requiring manual checks. The last characteristic is reparability,which describes the possibility to bring the system back into a consistent and correct state, evenif erroneous software was deployed.An architecture and software development patterns are evaluated to build an overall programmingmodel that provides the software characteristics. The overall architecture is basedon microservices, which facilitates decoupling and maintainability for the software as well asorganizations. Command Query Responsibility Segregation decouples read from write operationsand makes data changes explicit. With Event Sourcing, the system stores not only the currentstate, but all historic events. It provides a built-in audit trail and is able to reproduce differentscenarios for troubleshooting and testing.A demo process is defined and implemented within multiple prototypes. The design of theprototype is based on the programming model. It is built in Javascript and implements Microservices,CQRS and Event Sourcing. The prototypes show and validate how the programmingmodel provides the software characteristics. Software built with the programming model allowscompanies to iterate faster at scale. Since the programming model is suited for complex processes,the main limitation is that the validation is based on a demo process that is simpler and thebenefits are hard to quantify.