# Information and Communication Technology Solutions for the Circular Economy
## 4 Discussion on the Results--Conclusions  
The present paper surveyed a wide range of ICT-based solutions that act as pillars or facilitators for the successful development and application of CE models. The most prevalent result from Table 1 is that the majority of the solutions are more relevant to the \"reduce\" CE concept. This is fully in line with the hierarchy of the CE frameworks. Prioritizing \"reduce\" over \"reuse\", \"recycle\", and \"recover\" is of great importance, as it aids in preventing several complications (quality deterioration sometimes present while recycling/reusing, use of resources to recycle/restore, etc.) As all of the concepts of the 4R model are strongly interrelated, finding a solution in a specific CE concept category does not exclude the possibility of one solution being relevant to another CE concept as well. Another important remark is that many of the solutions employed several technologies from different categories. This can be justified by the fact that information and communication technologies are often connected with each other. Data Collection and IoT and Data Analysis and AI Algorithms were the two most popular general technological categories of all the analyzed solutions. IoT, Blockchain, Digital Platforms and Software Tools were the most popular technological subcategories. The adoption of the analyzed solutions for the CE transition cannot always be clearly prioritized, due to their complex interrelations and sometimes unique contributions. However, from our analysis we can underscore the importance of some solutions in terms of their completeness in supporting all four concepts of the 4R framework: (a) Cloud manufacturing and new business model supporting industrial symbiosis [24]; (b) Big data in support of CE as a whole [40]; (c) CE strategy design and adoption evaluation [50; 90]; (d) Education and training to raise awareness about and promote CE solutions [88; 91]. As the aforementioned solutions support all four concepts of the 4R framework, they can play a more central role in the CE transition. Novel circular business models can pave the way for the adoption of several CE-related technologies. Similarly, education and capacity building activities can raise consciousness about CE with both businesses and individuals, leading to the greater development and support of relevant technologies. Lastly, evaluation models for the CE can provide useful information and recommendations for forming more efficient strategies as well as for prioritizing the adoption of various circular solutions. Analyzing the papers in this literature review indicated not only the direct connections with the technologies utilized, but also the indirect ones. Technology and digitization have transformed the world's landscape. The form of today's businesses, manufacturing processes, healthcare, communication, education, mass media as well as of almost every other aspect of human lives has radically changed since ICT advancements began snowballing, a few decades ago. It would be a mistake to overlook the importance of all these advancements, even in seemingly irrelevant solutions. For example, designing an AR-based mobile application for supporting the CE today, would be impossible if it had not been for the advancements in computers, programming, communications, etc., of the previous decades. It would also be impossible if people had not been educated to use smartphones and the internet. The CE model is radically different from today's linear model of economy. Currently, there are many obstacles and challenges regarding the adoption of ICT solutions for the CE. Several of these challenges were identified in this paper. Consumer and business attitude, economic costs, environmental impacts, lack of education around the CE, and lack of familiarization with modern technologies were some of the most critical ones, while there are also many interconnections among them.