ITU‐T's Technical Reports and Specifications 865 Annex H Japan: Index system of SSC being discussed in the sub working group for SSC of the Telecommunication Technology Committee (TTC) Source: Telecommunication Technology Committee, Japan http://www.ttc.or.jp/e/ Structure of KPI [8]: The Telecommunication Technology Committee (TTC) in Japan has formed a sub working group for SSC meetings to discuss the index system of SSC. With the proposed KPIs of SSC [8], indicators are divided into four layers for simplicity, and positioned \"environment, economy, society, satisfaction\" as the first layer. Since the notion of \"society\" is broad, it is further split into \"safety\", \"health\", and \"comfort,\" then positioned in the second layer. The third layer includes indicators such as \"information security\" and \"ubiquitous\" from the ICT perspective. The fourth layer includes data to calculate the KPIs in the third layer. The main feature of the KPIs is that various units are used for data in the fourth layer as indicated in Table H.1, while all other layers use a monetary value as the unit. Table H.1 – Structure of KPIs * Indicates using a monetary value as the unit.