Researchers have found that about 70% of information systems (IS) development projects in Japan have failed, thus increasing the demand for solutions that will increase expected project success rates. In this study, we seek to explore such a solution by identifying factors that affect the degree to which Japanese IS development projects succeed or fail. We accomplish this by using an Internet-based questionnaire and statistical analysis. The questionnaire, which was primarily comprised of questions related to CMMI, yielded responses from 650 project managers who work for Japanese IT vendors. Multivariate analyses and structure equation modeling techniques demonstrated that seven factors, “Ordering Company's Skill and Requirement, ” “Project Planning, ” “Detailed Planning and Product Quality in Each Phase, ” “Project Monitoring and Control, ” “Change Requirement Management, ” “Skill and Teamwork of Project Members, ” and “Schedule Progress in Each Phase” influence project performance. Results also showed that these factors covary.