Refactoring is an increasingly practiced method in industrial software development. Stated simply, refactoring is an ongoing software improvement process that simplifies the internal structure of existing software, without changing its external behavior. The purpose is to improve the software and facilitate future maintenance and enhancement. Existing studies on refactoring mainly focus on its technical aspects and thus do not consider the team and human factors that influence its success. To identify the major facilitating factors for the success of refactoring, we interviewed 10 industrial software developers, and combined their responses with a study of the existing literature, formulated a model of refactoring success. The resulting conceptual model comprises both technical and non-technical factors. Technical factors include: level, testing and debugging, and tools, while the non-technical factors include: communication and coordination, support activities, individual capability/skills, and programmer participation. We propose to verify this model empirically through a survey of professional software developers (main body of refactoring practitioners). The survey design is provided.