A Product-Service Systems (PSS) is composed of service and product element to provide values for relevant stakeholders. A typical service interaction involves providers and receivers, and respective values are provided in a social interaction. When service channel is supported by physical touchpoints, receivers will interact with products, which may interact with providers. Thus, in PSS, various kinds of interactions occur in diverse social contexts. These social contexts can be repre- sented using graphs where nodes represent stakeholders and product touchpoints and attributed edges represent the interaction. Interaction among products as well as that of human stakeholders and that of human and product touchpoint can be described using such a graph-based representation. In designing and operating PSS with internet of things, social context representations could be used in analyzing and comparing key aspects of social interaction types to retrieve similar cases to exploit related interaction design strategies and operation know-hows.