The Claims about Test Driven Development

In the traditional software development process, unit-and functional tests are written after the code is implemented. However, recently agile software development methods were introduced which also change traditional testing practice. Test driven development (TDD) is a practice of eXtreme Programming (XP) where unit-and functional tests drive the development of the code. This means that the tests are written before the actual code that is going to be tested. It is claimed, among others, that TDD produces better code quality. The goal of this thesis is to collect all the claims. Evaluation is done in two steps. The first step is studying the literature for supporting or contradictory evidences. The second step is implementing two case studies: a GUI based cinema reservation system and a GUI based shop stock management system. One case study is done using a traditional software process, where the tests are written after the implementation, and the second case study is done using XP and TDD. The results of the case studies are then compared with the results from the literature. This thesis introduces the eXtreme Programming and Test Driven Development. The main focus is on collecting claims about Test Driven Development, and evaluated those claims. I would like to thank my supervisor, the professor Hubert Baumeister. Thanks for Hubert's guidance, correction and advice throughout the whole project.