# I4.0I: A New Way to Rank How Involved a Company Is in the Industry 4.0 Era
## 2 Related Work  
As a starting point on constructing the I4.0I, we conducted preliminary research about the status quo of Industry 4.0 maturity models and previously established indexes. We searched a collection of keywords on several research databases, using the following terms: \"Industry 4.0 maturity model\", \"Industry 4.0 maturity level\", \"Industry 4.0 maturity index\", and \"Industry 4.0 readiness model\". Regarding the data sources, we used the following ones: Google Scholar, ScienceDirect, SpringerLink, Scopus, and IEEE Xplore, filtering those articles that were published from 2015 up to January 2023 in order to obtain recent publications and also a good number of results. In addition, in order to obtain the most cited and recent references, we studied articles that analyzed Industry 4.0 maturity models [25; 26]. [PERSON] et al. [15] developed a maturity model focused mainly on business, processes, and organization, not encompassing the technology area. In addition, we perceived that the construction methodology and maturity levels were not well-explained, lacking details and explanations about the equations. Similarly, in [PERSON] and [PERSON] [16], the investigators proposed a maturity model to help companies define their goals in Industry 4.0 by analyzing their vision, creating a road map and reaching a final project. In their work, [PERSON] and [PERSON] [17] presented a model based mainly on information technologies (more precisely, CPS) and the defining characteristics of a technology for different maturity levels, describing their relationships and the development of a low and high maturity. It was also possible to notice that some of the steps described as CPS levels could be described as different technologies. The main idea of that model was not to seek the highest level of maturity possible but to determine the best and most significant level for each company. [PERSON] et al. [18] introduced a maturity model that enabled a company to classify its IT systems' landscape with a focus on Industry 4.0 requirements. Moreover, the recommended activities were shown for each stage of scanning, which allowed a company to reach the next phase of maturity. The analysis result was presented as maturity levels. The DREAMY model [19] divided processes into five categories, not focusing just on technologies. In that model, each process area could be considered a standalone module, so adding or removing one or more spaces was possible if they were not significant in certain industrial situations. It also identified strengths, weaknesses, and growth opportunities and outlined a road map for its digital transformation. [PERSON] et al. [20] presented their results with a radar graph, showing the nine dimensions determined and the level of maturity of a company in each of these dimensions, not giving a single number of classifications. The model embraced factors that were not related to technologies itself, such as the local government. Among all the models researched, the article elaborated by [PERSON] et al. [21] was the only one that presented the results numerically, which were obtained by averaging the values obtained by a questionnaire applied to the analyzed company. However, the paper did not detail the technologies involved with Industry 4.0 and therefore, the survey form was composed of vague answers. The Industry 4.0 Maturity Index [22] and IMPULS--Industrie 4.0 Readiness [23] were the models found that contained the most detailed methodology and technologies. The former defined four structural areas of the company and six levels of maturity. Then, the company, according to a questionnaire, was classified in one level of maturity for each structural area, resulting in a radar graph. Thus, it was possible to identify the capabilities that required improvement. The model considered some external aspects, such as employees' skills and their openness to change. In the paper written by [PERSON] et al. [23], six dimensions and five maturity levels were established.