Agile enterprise software development using domain-driven design and test first

In this paper we present the experience gained and lessons learned when the IT department at Statoil ASA, a large Oil and Gas company in Norway, applied Domain-Driven design techniques in combination with agile software development practices to assess the software architecture of our next generation oil trading and supply chain application. Our hypothesis was that the use of object oriented techniques, domain driven design and a proper object-relational mapping tool would significantly improve the performance and reduce the code base compared with current legacy systems. The legacy system is based on several Oracle databases serving a variety of clients written in Java, Gupta Centura Team Developer and HTML. The databases have a layer of business logic written in PL/SQL offering various system services to the clients. To validate our new object-oriented software architecture, we re-implemented one of the most computationally heavy and data intensive services using Test First and Domain-Driven design techniques. The resulting software was then tested on a set of servers with a representative subset of data from the production environment. We found that using these techniques improved our software architecture with respect to performance as well as code quality when running on top of our Oracle databases. We also tested the switch to an object database from Versant and achieved additional performance gains.