Abstract,Case study is a suitable research methodology,for software engineering,research since it studies contemporary phenomena in its natural context. However, the understanding of what constitutes a case study varies, and hence the quality of the resulting studies. This paper aims,at providing,an introduction to case study methodology,and,guidelines for researchers,conducting,case studies and,readers studying,reports of such,studies. The content is based on the authors’ own,experience from conducting,and reading case studies. The terminology,and,guidelines are compiled,from,different methodology,handbooks,in other research domains, in particular social science and information systems, and adapted to the needs,in software,engineering. We,present,recommended,practices for software engineering,case studies as well,as empirically,derived,and,evaluated,checklists for researchers and readers of case study research. Keywords,Casestudy.Research methodology.Checklists .Guidelines