Abstract
Our company conducts postmortem on the past failure projects. Not only people involved in the failure project but also executive officers of the division and managers of other projects participate in the postmortem. Participants draw lessons on project management from the failure project at the postmortem. There are some analysis processes to analyze accident or human errors. But, it was difficult to apply these conventional analysis processes to the field of project management because of the following features. (1) The causal relationship between environmental factors and decision-making is very complex. (2) Project management greatly depends on human behaviors. (3) There is no surefire manual in project management. To solve the above problems, we defined an analysis process. Our analysis process is an improvement of Variation Tree Analysis. With this process, we can analyze and store failure project cases.