## 2 Concepts Review
### Smart City Model  
The SMART criterion emerged in the 1980s and is an acronym of the objectives of a business management proposal: specific, measurable, achievable, relevant, time-bound [14]. Later these criteria became a concept which was applied to different disciplines of study, with the intention of improving results in terms of increased efficiency in resource management by coordinating information between different systems. From an organizational point of view, information control in cities would allow cross-communication between the actors involved in the management of cities and citizens [15]. Thus, through the advancement of ICT, the coordination of information between systems improves the SMART management approach towards its application in more complex systems such as cities [16; 17; 18; 19; 20]. From an integral and holistic point of view, the smart city concept brings together a series of strategic proposals, which seeks for the development and future growth of cities in order to make them competitive, sustainable, and able to offer a high quality of life to urban population [21; 22; 23]. With the control of information, the crux of these management proposals is to find out the modus operandi of the demand for urban services in order to efficiently manage the resources available: natural resources (energy, water, air), infrastructures, economic resources, people, and knowledge. Figure 3: Structure of the indicators of the pathway calculator of the WEC (World Energy Council). Source: Created by authors using data from [13]. Figure 2: Distribution of the 125 countries of the ETI (Energy Trilemma Index) 2017 by regions and GDP groups per capita. Notes: Regions are divided (greatest to least presence) into Europe with 41 countries (32.8%), Sub-Saharan 25 (29%), Asia 22 (17.6%), LAC 19 (15.2%), MENA 15 (12%) and North-America 3 (2.4%). The GDP groups are divided as: Group-I has 34 countries (27.2%), Group-II has 38 (30.4%), Group-III has 27 (21.6%), and Group-IV has 26 (20.8%). Source: Created by authors using data from [12]. Since the early 1990s, the smart city concept has been a subject of study (a search for the term \"smart city\" in the Web of Science (WOS) and Scopus return the first references to it in 1991 [24] and 1997 [25]). From this time until the middle of the current decade, various authors have published their views on the definition without reaching an agreement about the scope of this concept [26; 27; 21; 28]. Even so, the definitions presented included proposals for the working taxonomy of this type of city, such as in [26], evaluation and classification methodologies as in [29; 30], planning in [31], suggestions for strategies to successfully implement the smart model in cities in [28; 32; 33], and in the case of [34], a reference initiative for this purpose, in this case it was Barcelona. These publications also included methods to integrate technological devices into the services that are to be provided in cities, such as [35]. Working with the same concept, to date, the study of the smart city concept has been done by international (the European Union's approach to the smart city concept considers energy sustainability to be a priority on the basis of the main energy resource being energy efficiency [36; 37], and the conception, development, and integration of urban energy production and use. Its objective is to improve efficiency as well as reduce energy consumption and the emission of GHG [38]) organizations [22] and tech companies [39], companies in the financial sector [40], as well as centers for economic, financial, technological, and social studies. The large number of parties involved in the defining of the smart city concept shows the magnitude of its importance in the future of cities and its ability to catch the attention of the different parties involved in urban growth and development. The ultimate aim of these parties is to work on two closely related aspects of contemporary cities: quality of life and competitiveness [41].