Abstract
For project quality assurance, we used a variety of rules and checklists. However, the team building could not be hierarchical because of the declining population of young people in a recent project. For both managers and leaders, there was a gap of team members and experience levels. In addition, the project employed multiple sub-contractors. Thus, it was difficult to bring quality awareness to the entire team. As a result, it increased the trouble caused by SE works. This text reports on an actual example of the cause and the realistic measures taken.