Abstract
The recent diffusion of Internet is leading to more Internet-based mission-critical systems at companies, schools, and governmental agencies with the result that high system availability is more important than ever. As systems grow in scale and become more complicated, however, it becomes difficult to cope with all events that arise using the limited system administrator resources.
In this study, it is proposed how to support the operation of system administrators incorporating the concept of visible Network services to deal with this issue. This should enable the system administrator to manage a large and complicated system with limited system administrator resources, allowing them to plan an operation strategy with an emphasis on system availability.