I. Introduction
The innovative systems of smart cities are defined by IBM as the use of information and communication technology to sense, analyze and integrate the key information of core systems in running cities. The smart cities can provide innovative intelligent services and urban management thereby promoting a more efficient, harmonious and convenient process for modern cities [28]. The exploration of user needs by gathering user feedback is crucial for a successful innovation development. Therefore, the Open Living Lab, where everyone can participate [10], must be adopted in the management and the development process of the smart cities systems. Despite the studies provided by the previous literature, which show that the living lab can be a conceptualization, a context, or a methodology, the multiplicity of approaches, an involvement of users and multiple stakeholders, as well as the importance of the real life environment, are commonly addressed by the living lab definitions [21] [20]. To facilitate the identification of the actors that can drive the innovation, Leminen, Westerlund, and Nyström [23] put forward four different types of living lab, namely utilizer-driven, enabler-driven, provider-driven and user-driven. Moreover, based on the customized tools and iterative innovation processes, a novel typology was introduced: linearizer, iterator, mass customizer and tailor [22]. Bergvall-Kåreborn et al., [8] set forth the FormIT method that facilitates co-creation in the living lab. Furthermore, Tang and Hämäläinen [30] define a process model comprising five iterative phases, namely requirements, co-design, prototyping, test and tracking, and commercialization.