In the software industry, there are several processes and methodologies that exist. The traditional processes and Agile methodologies have their own strengths and weaknesses. Agile methodologies overcome some of the weaknesses of traditional processes. Although in the recent years Agile methodologies have been used by software development companies, there is still a high ratio of software failures when compared with core engineering processes. The adoption of these processes in software development could alleviate software failures. This systematic study reviews the strengths and weaknesses of both traditional processes and Agile processes. The search strategy resulted in 91 papers, of which 25 primary studies are investigated between 2012 and 2019. The detailed search strategy has been presented in this study along with future directions.In a tertiary study done in [18], it has been revealed that test driven development (TDD) has a very positive impact on external quality of a product. The quality attribute included external quality, complexity, code size, etc. However, no conclusion was made on the impacts of TDD on code size. Test driven development is one of the most advantageous approaches that has produced several successful products