Stored procedures are used as the current database logic for SAAB’s data model of the fighter aircraft JAS-39 Gripen electrical schemas. Since the database model was developed in 2000, a research and tests needed to be carried out to decide on whether updating the database to today's technology is applicable. Therefore, Object-Relational Mapping (ORM) is to be researched, tested and compared to stored procedures using test-driven development (TDD)concerning an important factor, that Stored procedures are well-known for, which is querying performance of the database. Moreover, how maintainability and flexibility [1] can affect decision between Stored procedures or migrating to ORM based on our subjective experience. NHibernate and Entity Framework are the two ORM solutions considered sinceSAAB uses C# in this project. The process of this project is run using scrum of the agile software development to maintain an iterative progress throughout the project timeline. In this paper, the process and methodology are covered in details and also the comparison with the test results. These results eventually lead us to the answer that ORM is not a suitable technology, and stored procedures still dominate the querying performance for SAAB’scurrent database.