What is a systematic review?
"A systematic literature review (often referred to as a systematic review) is a means of identifying, evaluating and interpreting all available research relevant to a particular research question, or topic area, or phenomenon of interest. Individual studies contributing to a systematic review are called primary studies; a systematic review is a form of secondary study."  Kitchenham and Charters
Systematic Reviews are methods under the Evidence-Based Software Engineering initiative which states that its goal is:
"to provide the means by which current best evidence from research can be integrated with practical experience and human values in the decision making process regarding the development and maintenance of software"  Kitchenham et al
 Kitchenham, B.A. and S. Charters (2007) Guidelines for performing systematic literature reviews in software engineering, Technical Report EBSE-2007-01, School of Computer Science and Mathematics, Keele University.
 Barbara A. Kitchenham, Tore Dyba, and Magne Jorgensen. 2004. Evidence-Based Software Engineering. In Proceedings of the 26th International Conference on Software Engineering (ICSE '04). IEEE Computer Society, Washington, DC, USA, 273-281.