**3. Research Methodology**

We undertook an initial informal search, which, together with personal knowledge, confirmed that there exist a relevant number of contributions on the EI topic and that a systematic review would be appropriate. It also provided the information needed to guide the manual search process. Accordingly, a survey of articles regarding EI spanning 13 years (from January 2011 to February 2023) was conducted in accordance with the guidelines of the PRISMA statement. After the record screening and the report selection processing, we analyzed a total of 50 works. However, they refer to specific domains (e.g., robotics [18] or cyber-security [19]) or technology (e.g., embedded intelligence for

FPGA [20]), to narrow contributions (e.g., a novel version of an algorithm or an optimized model [21,22]), and to broader surveys/review papers outlining definitions, goals, and roadmaps for EI. We decided to focus specifically on the latter and performed a further handmade selection, which produced a systematic analysis literature in the form of a tertiary study of 14 publications. The undertaken *search plan* is summarized in Table 1, while Figure 2 depicts the flow-chart of the PRISMA-based selection process, detailed in the following subsections.
