IOT has seen countless potential applications that can improve our lives dramatically, but after years of efforts by numerous companies and organizations, the beautiful dreams are yet to be realized. The main obstacles are cost and energy consumption constraints of the devices and systems, which still cannot be contained. As a step forward in improving the reliability and reducing the cost and energy consumption of IOT devices and systems, we propose a high-level model for efficient design-space exploration, which is called the symbiotic system (SS) model. Based on that, we propose a quorum-sensing model for SS to improve the reliability of IOT systems that contain subsystems. Experimental result shows that, with the SS approach, the lifetime of an example IOT storage system with 50K failure-in-time/Mb nodes can be extended by 74.41 %. In addition, to double the lifetime of the system, only 5% additional repair resource is required. In short, by the SS model, it is possible for an IOT system to achieve low cost, low energy consumption, and high reliability.