**2. State of the art on "Industry 4.0"**

A comprehensive overview of the state of the emerging industrial revolution is essential to understand the *phenomenon* around the world. To this purpose an investigation on Scopus database, the largest abstract and citation database of peer-reviewed literature, was carried out. The methodological approach used for literature review survey is shown in **Figure 2**.

Search string used in the literature survey was "Industry 4.0." The string was defined according to the standards of Scopus database. Articles, conference, and book chapters in which the string was found in *keywords* were analyzed. The analysis on Scopus pointed out that from 2012 (the year in which the first article was published) until October 2017 (the period of research), there is a constant, growing interest on this topic. Considering this time period, the Scopus database returns 886 results related to the topic "Industry 4.0." From 2015 onward scientific production has increased considerably, as shown in **Figure 3**.

The survey confirmed that most of the publications are German. It is worthy to note that German publications are quadruple compared to Chinese publications, and compared to Italian publications, the value is seven times more as shown in **Figure 4**.

The search was refined considering only articles. The research shows 274 published articles since 2012. Since 2015, there is a growing trend of publications on these issues. This strong interest is certainly due to the strong attractiveness of the issues of smart manufacturing both

from a research and business point of view. The analysis pointed out that 73% of the analyzed publications refers to engineering issues, 39.4% refers to communications issues, and 20.4% refers to business process management. Analyzing the 274 articles found, the search was more refined using seven specific keywords that characterize "Industry 4.0" as detailed

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below:

**Figure 4.** Documents by country.

**Figure 3.** Documents by year.

**Figure 2.** Literature review methodological approach.

Fourth Industrial Revolution: Current Practices, Challenges, and Opportunities http://dx.doi.org/10.5772/intechopen.72304 5

**Figure 3.** Documents by year.

**2. State of the art on "Industry 4.0"**

4 Digital Transformation in Smart Manufacturing

**Figure 2.** Literature review methodological approach.

A comprehensive overview of the state of the emerging industrial revolution is essential to understand the *phenomenon* around the world. To this purpose an investigation on Scopus database, the largest abstract and citation database of peer-reviewed literature, was carried out. The methodological approach used for literature review survey is shown in **Figure 2**.

Search string used in the literature survey was "Industry 4.0." The string was defined according to the standards of Scopus database. Articles, conference, and book chapters in which the string was found in *keywords* were analyzed. The analysis on Scopus pointed out that from 2012 (the year in which the first article was published) until October 2017 (the period of research), there is a constant, growing interest on this topic. Considering this time period, the Scopus database returns 886 results related to the topic "Industry 4.0." From 2015 onward

The survey confirmed that most of the publications are German. It is worthy to note that German publications are quadruple compared to Chinese publications, and compared to

The search was refined considering only articles. The research shows 274 published articles since 2012. Since 2015, there is a growing trend of publications on these issues. This strong interest is certainly due to the strong attractiveness of the issues of smart manufacturing both

scientific production has increased considerably, as shown in **Figure 3**.

Italian publications, the value is seven times more as shown in **Figure 4**.

from a research and business point of view. The analysis pointed out that 73% of the analyzed publications refers to engineering issues, 39.4% refers to communications issues, and 20.4% refers to business process management. Analyzing the 274 articles found, the search was more refined using seven specific keywords that characterize "Industry 4.0" as detailed below:


**Figure 5** describes the number of articles classified for each keyword.

In the rest of the papers, other keywords are cited. Furthermore, it is worthy to note the relationship between different keywords in the same article. The results are shown in **Table 1**. The most important relationships are developed between cyber-physical systems and big data systems.

**Table 2** shows the most cited analyzed articles. In detail, the most cited article is proposed by Lee et al. that present an integrated five-level system for the implementation of a cyber-physical system [1]. Then, Davis et al. present the smart manufacturing approach based on intelligent cyber-physical components for smart organization management [15]. In 2015, Posada et al. describe the positioning of visual computing within the smart manufacturing system to indicate specific future scenarios [16]. In 2016, Kang et al. develop a literature review analysis identifying and analyzing different articles related to smart manufacturing to create a clear view of existing technologies, practices in companies, and future trends [17]. Finally, Yue et al. analyze the development of industrialization and technology digitization by presenting a model supported by a cloud system for managing a sustainable industrial system [18].

**Authors Title Year Citations**

Smart manufacturing, manufacturing intelligence, and

Visual Computing as a Key Enabling Technology for

Smart manufacturing: past research, present findings,

Cloud-assisted industrial cyber-physical systems: an

2015 258

2012 103

2015 45

2016 38

2015 19

4.0-based manufacturing systems

demand-dynamic performance

and future directions

insight

Industrie 4.0 and Industrial Internet

Lee, J.; Bagheri, B.; Kao, H. A cyber-physical systems architecture for Industry

**CPS IoT Big data Automation Cloud Simulation Additive**

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CPS 8 21 2 1 3 1 IoT 9 1 — 1 3 Big data 3 — 6 1 Automation — 1 2 Cloud — — Simulation —

Additive

**Table 1.** Relationship between keywords.

Davis, J.; Edgar, T.; Porter, J.; Bernaden, J.; Sarli, M.

Döllner, J.; Vallarino, I.

B.H.; Noh, S.D.

Zhou, K.

Posada, J.; Toro, C.; Barandiaran, I.;

Kang, H.S.; Lee, J.Y.; Choi, S.; Kim,

Yue, X.; Cai, H.; Yan, H.; Zou, C.;

**Table 2.** Most cited articles.

The key objective of Industry 4.0 is to be faster and to drive manufacturing to be more efficient. The main technology used in the context of Industry 4.0 is **cyber-physical systems (CPS)** [19]. CPS are considered a Key Enabling Technology (KET) in the fourth industrial revolution.

**3. Digital technologies and industrial transformations**

**Figure 5.** Number of articles classified for keywords.


**Table 1.** Relationship between keywords.

• *Cyber-physical systems*. There are 55 articles (20.07%) that contained the keyword (CPS) between the keywords. The first publication dates back to 2012, but since 2015, a "stable"

• *Big data or digitalization or digital*. There are 43 articles (15.69%) that contained the previously defined keywords. The first publication dates back to 2015, and in 2016–2017, there

• *Internet of things (IoT) or wireless*. There are 50 articles (18.25%) that contained the previously defined keywords. The first publication dates back to 2016, while in 2017 there has been a downward trend of about 10 publications. This trend could turn out to grow, as several

• *Automation or artificial intelligence or robotics*. There are 18 articles (6.57%) that contained the previously defined keywords. The interesting publications for the analysis are from 2015 to

• *Additive manufacturing or 3D printers*. There are six articles (2.19%) that contained the previously defined keywords. The first release dates back to 2014; there are other publications

• *Cloud*. There were 10 articles (3.65%) that contained the previously defined keywords. The

• *Simulation/augmented/virtual reality*. There were 10 articles (3.65%) that contained the previously defined keywords. The first publication dates back to 2012. But in the 2-year period

In the rest of the papers, other keywords are cited. Furthermore, it is worthy to note the relationship between different keywords in the same article. The results are shown in **Table 1**. The most important relationships are developed between cyber-physical systems and big data systems.

2016–2017, research began to produce more complete and complete documents.

first release dates back to 2015. There are no such publications for 2017.

**Figure 5** describes the number of articles classified for each keyword.

research on this issue has started.

6 Digital Transformation in Smart Manufacturing

was a growing, extremely positive trend.

months remain missing at the end of 2017.

until 2017, but the number is very limited.

2017 which show a positive trend.

**Figure 5.** Number of articles classified for keywords.


**Table 2.** Most cited articles.

**Table 2** shows the most cited analyzed articles. In detail, the most cited article is proposed by Lee et al. that present an integrated five-level system for the implementation of a cyber-physical system [1]. Then, Davis et al. present the smart manufacturing approach based on intelligent cyber-physical components for smart organization management [15]. In 2015, Posada et al. describe the positioning of visual computing within the smart manufacturing system to indicate specific future scenarios [16]. In 2016, Kang et al. develop a literature review analysis identifying and analyzing different articles related to smart manufacturing to create a clear view of existing technologies, practices in companies, and future trends [17]. Finally, Yue et al. analyze the development of industrialization and technology digitization by presenting a model supported by a cloud system for managing a sustainable industrial system [18].
