IoT systems provide new possibilities for augmenting daily activities of the people, which can be embedded in different settings and across contexts. Proprietary technologies have been extensively deployed throughout multiple IoT platforms, where such systems are closed in many cases. This closed nature complicates the development and customization processes for developers and end-users. To our knowledge, existing solutions do not address the sustainability requirements for the IoT architecture in terms of orchestrating smart services and devices in a more open and common way. Having a lot of standards brings us to the situation that we cannot utilize any standard into the design and development of IoT systems. Thus, we believe that we should start thinking less about standardization, and more about open approaches within IoT domain. In this paper, we use the concept of an open architecture that supports flexibility, customizability, and extensibility as a basis to address some of the above mentioned challenges.