I. Introduction
Network services which based on information and communication technology (ICT services) are now widespread among the world. A lot of organizations depend on ICT services for their daily activities. Many kinds of public services are now served through computer networks. For example, in a hospital, medical records of patients are stored as electronic health records in storage servers, and IP-based phone services are replacing traditional telephone services. Thus, ICT services/systems are social infrastructures and vital to our daily life. Therefore, if a system suffers catastrophic damage by a large-scale natural disaster, in accordance with their business continuity planning, system administrators of each organization operating some kind of ICT services must restore the system and restart the service as soon as possible [1]. To rapidly restore damaged systems, many studies have been conducted, such as movable datacenter [2]. However, it is not reasonable to suppose that a sufficient number of well-trained administrators are prepared in emergency situations to make them work for system restoration tasks. Especially, organizations such as public institutions sometimes have no staffs for services management, because they often outsource operation tasks of their systems to other companies. As a first step for rapid restoration of damaged systems in emergency situations, securing human resources who have enough knowledge and experiences is important.