Context. Distributed software development becomes increasingly common with the trend of globalization. Scrum, as one of the methods to realize agile, is gradually accepted by more and more people and applied to actual industrial production. Although there have been some successful cases of distributed Scrum team development, the description of these successful experiences may not be exhaustive enough and not applicable to all teams. There is still a great demand for actual industrial case studies, especially related research on specific teams and detailed challenges encountered. In order to enable more distributed scrum teams to better handle various challenges in the development process, further research on the challenges the teams encounter and how to solve, mitigate, and avoid the impact of these challenges is necessary.

Objectives. The main objectives of this research are to investigate the challenges faced by distributed Scrum teams in the development process, the factors that cause them, and how to deal with these challenges.

Methods. We conducted a systematic literature review and obtained the most common problems encountered by distributed Scrum teams and parts of the factors that caused this problem. On this basis, we conducted case studies on 2 large companies in Asia. We used archived data to know the basic information of the case team and a semi-structured interview was used to understand the problems they encountered and their opinions.

Results. During this study we found that the most common challenge encountered by distributed Scrum teams was "Communication among stakeholders". Totally 16 factors were found that could cause this challenge. The two main factors were “Team members have insufficient knowledge or different skill levels” and “Are not familiar with each other or have differences”. And 42 solutions were provided after we integrated the information obtained.

Conclusions. We conclude that communication is a matter of great concern, whether in the literature we used or in our case team. The factors and solutions given are only for reference by teams of similar types and development backgrounds. Further researches on other different types of teams and other challenges encountered are also necessary.