Another major challenge of IoT is the security aspect.
As the IoT system grows, the significance of the security also becomes a big concern.
Simply hacking a household device does not cause much harm compared to shutdown of a power grid which cause power outage to a large geographical area.
Security upgrades are usually implemented by including additional security patches to the OS.
IoT devices and system should support future upgrades / updates as well.
Fatal security failure could happen due insufficient security measures of IoT devices and gadgets when competitors within the industry trying to secure their position in the market.
Since IoT technology has not been standardized, many small scale, medium scale and startups will try their part to become a player in the IoT business without enough security measures.