The success or failure of software development projects depends on various reasons. Among them, in this
paper, we will focus on the human relationship among the project members of both customers and developers. They
form both formal and informal social networks. Using the concepts of social network analysis, we have carried out
two case studies on software development projects in business domains: the one is successful and the other is not. We have used questionnaire surveys to depict the characteristics of communication networks among members. We have analyzed what factors increase the difficulty and what characteristics the key persons or ‘agents’ show inside the
project teams. The ‘agents’ will negotiate with the other members to lead the projects succsessful. The study results have suggested that the existence of ‘agents’ in customer and developer sides is critical for effective software
development.