Assuring safety in the home network system (HNS) is a crucial issue to guarantee high quality of life. In this position paper, we first review our previous work, formulating three kinds of safety for the HNS integrated services: local safety, global safety, and environment safety. We then present a method that validates safety for integrated service. Finally, we discuss a perspective in how the safety can be assured when considering the feature interaction problem. 1 Formalizing Safety in Home Network System The home network system (HNS, for short) is comprised of networked home appliances and sensors, which is one of the most promising applications of the emerging ubiquitous computing technologies. The HNS enables flexible integration (or orchestration) of different home appliances and sensors through the network, which achieves value-added integrated services [5]. In developing and providing the HNS integrated services, the service provider must guarantee that the service is safe f...