Experience of Industry Case Studies: A Comparison of Multi-Case and Embedded Case Study Methods

Context: Case studies are a useful approach for conducting empirical studies of software engineering, in part because they allow a phenomenon to be studied in its real-world context. However, given that there are several kinds of case studies, each with its own strengths and weaknesses, researchers need to know how to choose which kind to employ for a specific research study. Aim: The objective of this research is to compare two case study approaches: embedded, longitudinal case studies, and multi-case studies. Approach: We compared two actual software engineering case studies: a multi-case study involving interviews with 46 practitioners at 9 international companies engaged in offshoring and outsourcing, and a single case, participant observation embedded case study lasting 13 months in a mid-sized Irish software company. Both case studies were exploring similar problems of understanding the activities performed by members of scrum development teams. Results: We found that both multi-case and embedded case studies are suitable for exploratory research (hypothesis development) but that embedded research may also be more suitable for explanatory research (hypothesis testing). We also found that longitudinal case studies offer better confirmability, while multi-case studies offer better transferability. Conclusion: We propose a set of illustrative research questions to assist with the selection of the appropriate case study method.