Introduction
With the advancement of modern technology and tight business processes, firms face difficulty due to fierce rivalry and the increasing complexity of international trade (Bojnec & Ferto, Reference Bojnec and Ferto2009; Lei et al., Reference Lei, Hui, Xiang, Zelin, Xu-Hui and Evans2021). Thus, pushing the business flow through the supply chain (SC) (Abdel-Basset, Manogaran, & Mohamed, Reference Abdel-Basset, Manogaran and Mohamed2018; Liu et al., Reference Liu, Zhang, Niu, Liu and He2022). According to Lou, Liu (Lou et al., Reference Lou, Liu, Zhou and Wang2011), an SC is a network of providers, manufacturers, retailers, distribution centers, and clients via which raw materials are purchased, converted, manufactured, and supplied to the appropriate client. Moreover, SC will create market value where single firms are not self-adequate. Therefore, single firms can no longer become a generator of economic growth. Instead, these chains should coordinate with the whole network of organizations to produce and deliver products and services to end-users aiming for some goals such as sustainability (Lou et al., Reference Lou, Liu, Zhou and Wang2011; Pan et al., Reference Pan, Zhuang, Zhou and Yang2021).
As a complex business, supply chain management (SCM) entails having the right things in the appropriate quantity at the proper time, in the right position, for the right price, and in the right situation for the appropriate client (Wu et al., Reference Wu, Yue, Jin and Yen2016). SCM's extremely functional and economical operations rely on transmitting information and material flows as a complicated network of providers, manufacturers, distributors, warehouses, and retailers (Lou et al., Reference Lou, Liu, Zhou and Wang2011). Nevertheless, issues like delivery, overstocking, delays, and stocks are expected in true SC due to the typical SCM system's complexity, unpredictability, susceptibility, and expense. Unsurprisingly, the physical handling of delivered commodities results in human mistakes, leading to large economic losses.
As a result, the SC must become more competent to meet these problems. A competent SC is defined as a contemporary and integrated system that encompasses everything from isolated, single-firm, and regional applications to the full and systematic deployment of SC (Abdel-Basset, Manogaran, & Mohamed, Reference Abdel-Basset, Manogaran and Mohamed2018). It provides cheaper, better, and faster items that SC manager desires.
The fast advancement of information technology (IT), particularly the use and growth of the internet, has resulted in higher intelligent manufacturing and networked organization modes (Cao et al., Reference Cao, Zhang, Liu, Sun, Cao, Nowak, R. and Lv2022a; Chen et al., Reference Chen, Liu, Zhu and Li2020; Vahdat, Reference Vahdat2020). Moreover, the ultimate success of the SC is determined based on the success in coordination, integration, and management of the entire business process SC. Thus, the introduction of the internet aids in achieving the basic aim of creation in SCM, enabling information exchange in SCM while lowering overall cost, boosting operational effectiveness, and increasing competitive advantage. Internet of Things (IoT) is the Internet's next-generation network (Cao et al., Reference Cao, Ding, Wang, Lv, Tian, Wei and Gong2022b; Lou et al., Reference Lou, Liu, Zhou and Wang2011), which uses wireless data transfer, radio frequency identification, radar sensors, computers, and other technology to build a proper Internet that covers the whole globe (Christopher, Reference Christopher2012; Yan et al., Reference Yan, Jiao, Pu, Shi, Dai and Liu2022). Organizations can accomplish pervasive connectivity among objects (things), automotive data collection, sensor fusion, real-time processing, and ubiquitous computing in the physical world by implementing IoT technology and virtual reality (Lou et al., Reference Lou, Liu, Zhou and Wang2011; Sui et al., Reference Sui, Marelli, Sun and Fu2020; Yang et al., Reference Yang, Zhu, Wang, Wang and Xiongn.d.).
While facilitating the fast creation of IoT apps, the present IoT-centric design has resulted in many isolated data silos that limit the IoT's full potential for holistic data-driven business applications. In addition, remote IoT technology platforms have privacy and security issues (Wu et al., Reference Wu, Zheng, Xia and Lo2022; Yang et al., Reference Yang, Chen, Xiong, Xu, Liu and Zhang2021; Zheng et al., Reference Zheng, Xun, Wu, Deng, Chen and Sui2021). Blockchain is widely known as a decentralized option for data organization, enabling the peer-to-peer transfer of digital assets without intermediaries (Aste, Tasca, & Di Matteo, Reference Aste, Tasca and Di Matteo2017). Besides that, it can resolve financial transactions without the assistance of banks and other reliable agencies. Al-Rakhami and Al-Mashari (Reference Al-Rakhami and Al-Mashari2021) as blockchain has features such as non-tempering, consensus mechanism, and a smart contract (Yan et al., Reference Yan, Yin-He, Qian, Zhi-Yu, Chun-Zi and Zi-Yun2021). In addition, the security of exchanging distributed data is ensured by blockchain technology which can provide a significant impact on organizational governance. Additionally, it may modify how those involved in the SC organize their interactions and how they communicate and share goods and data (Min, Reference Min2019). Therefore, blockchain technology has provided a viable alternative for the security of IoT-based information systems. IoT devices may submit data to a shared transaction repository with tamper-resistant records using a blockchain. It allows business partners to access and deliver IoT data without the need for centralized control and administration (Pal & Yasar, Reference Pal and Yasar2020).
To provide comprehensive knowledge regarding integrating blockchain technology, IoT, and SCM. We, therefore, conducted a bibliometric analysis. According to (Hood & Wilson, Reference Hood and Wilson2001), bibliometrics is an established and reliable method that provides knowledge about a research field's evolution and conceptual structure by employing mathematical and statistical methods (Callon, Courtial, & Laville, Reference Callon, Courtial and Laville1991). Bibliometric analysis is used in this research to demonstrate blockchain-based IoT for developing a secure SCM system. We hope to learn more about the present scientific state of blockchain-based IoT for SCM by doing bibliometric and co-citation analyses. A comprehensive view of the current literature can help develop themes (Torraco, Reference Torraco2016). Hence, the present investigation uses bibliometric analysis to simplify the present literature in the SCM domain related to blockchain-based IoT, which will aid future researchers in identifying possible research themes and concerns. It will also assist beginners in understanding and gaining access to it fast.
The following is the article's structure. Section 2 demonstrates the related survey and overviews the papers about blockchain-based IoT literature in SCM. Section 3 presents the research methodology. The analysis outcome is presented in Section 4. The study's conclusion and potential research directions are discussed in Section 5.
Related work
Zhang, Gong (Zhang et al., Reference Zhang, Gong, Brown and Li2019) carried out a study that used content analysis tools to perform a full systematic literature assessment on blockchain usage in the food SC. They suggested four ideas and five possible difficulties in their study. The advantages and drawbacks of implementing blockchain in food SCM were also discussed. Nevertheless, this study was not systematic research; therefore, the article selection process has not been stated. Further, there is no comparison of articles provided in the article. Besides that, only a few articles have been investigated.
Aich, Chakraborty (Aich et al., Reference Aich, Chakraborty, Sain, Lee and Kim2019) concentrated on the distinctions between traditional and blockchain-based SCs. This report also discussed the advantages and drawbacks of deploying blockchain in various industries. Nevertheless, this review was not conducted systematically; therefore, the article selection process has not been stated. Further, the paper also does not mention future work or outstanding problems.
Moreover, Duan, Zhang (Duan et al., Reference Duan, Zhang, Gong, Brown and Li2020) studied blockchain implementation in the food SC and used a content-analysis-based literature review. This review presented a fundamental and thorough grasp of blockchain and its possible consequences. They also listed five significant obstacles to using blockchain in the food SC. Nevertheless, the evaluation was not conducted systematically; therefore, the article selection process has not been stated. Besides that, it excluded the IoT concern discussed in this paper. Further, future work and unresolved concerns have not been adequately addressed at the end of the paper.
Sangeetha, Shunmugan (Sangeetha, Shunmugan, & Murugan, Reference Sangeetha, Shunmugan and Murugan2020) used a systematic review technique to research blockchain for IoT-enabled SCM. They concentrated on new SCM approaches that included blockchain and IoT connectivity. They also discussed the merits and downsides of using blockchain and IoT to control SCs. Nevertheless, this work did not conduct a systematic review and did not compare certain comparable studies in their research. Further, the paper supplied no information about future work and open issues.
Furthermore, Khan and Yu (Khan & Yu, Reference Khan and Yu2021) looked at the organization theory employed in the Blockchain technology literature through the lens of operations and SCM. They discovered that six organizational methodologies, namely resource-based perspective, agency theory, network theory, institutional theory, information theory, and transaction cost analysis, were employed in Blockchain technology literature in SC-related disciplines. Nevertheless, this assessment was not systematic research; therefore, the paper selection procedure is not stated clearly. Moreover, only a few articles have been investigated, and there were no future works, and open issues described clearly in the paper.
In another survey, Berneis, Bartsch (Berneis, Bartsch, & Winkler, Reference Berneis, Bartsch and Winkler2021) investigated blockchain in logistics and SCM. They concentrated on the shortcomings of case studies and real instances published. This study discussed cluster analysis about the use of blockchain technology. They also offered a tangible illustration of how blockchain technology may be used in SCM and logistics. In contrast, this research was not a scientific investigation. Further, the paper has not adequately discussed future works and unresolved concerns.
Integrating trust and blockchain technology into SCM was a priority for Batwa and Norrman (Batwa & Norrman, Reference Batwa and Norrman2021). This paper explained how using blockchain in SCM might affect trust. They also suggested a research plan to go along with it. They uncovered a deficit in connecting trust theories to blockchain applications, particularly SCM. It was not systematic research; it was restricted to cluster-based methodologies. Therefore, the paper has some drawbacks, such as the papers are not compared ultimately, and future work and unresolved concerns have not been adequately discussed.
Finally, Shwetha and Prabodh (Shwetha & Prabodh, Reference Shwetha and Prabodh2021) described the present work and study on food SCM utilizing blockchain technology. This report also included future research trends and new studies in food traceability systems. Nevertheless, this evaluation was not conducted systematically, and certain articles in the field of blockchain-based IoT in food SCM were not included.
To summarize, systematic reviews are crucial in selecting papers. However, none of the mentioned surveys provide a comprehensive SLR of present blockchain-based IoT in SCM systems, including future challenges, classification, and the strong impact of blockchain-based IoT in SCM systems. Eventually, the outcomes from the analysis articles above found that most survey papers lack classification and comparison of relevant topics. Moreover, the selection procedures are not well stated. Further, the most important for other researchers as a guide, such as future work and unresolved topics, have not been thoroughly explored in these papers (Table 1).
Table 1. Overview of existing literature on blockchain in SCM
Research methodology
This work used bibliometric analytic techniques to investigate the architecture and substance of blockchain technology that enabled IoT and SCM to address the questions. A quantitative examination of books, journals, or other publications is known as bibliometrics. In the last few years, systematic bibliometric analysis has been used in multiple professional domains to display knowledge status, characteristics, evolution, and developing trends (Doewes et al., Reference Doewes, Gharibian, Zaman and Akhavan-Sigari2022; Guo et al., Reference Guo, Huang, Guo, Guo, Li, Liu, Ezzeddine and Nkeli2021). The analysis included word frequency, citation analysis, and counting publications by the unit of analysis (e.g., authorship, country, affiliations, and so on) (Ayoko, Caputo, & Mendy, Reference Ayoko, Caputo and Mendy2022; Vahdat & Shahidi, Reference Vahdat and Shahidi2020). Therefore, a significant quantity of academic research may be presented using bibliometric techniques, which can be seen from a micro to macro viewpoint (van Raan et al., Reference van Raan2005).
Hence, the investigation concentrates on comprehending how research into the application of blockchain-enabled IoT in SCM and similar topics have grown due to the technology's inception. To cover the most up-to-date utilization of these technologies in SCM, we chose the last five years, 2016–2020 (extending to early 2021), as the time frame for the literature review. We also utilize Web of Science (WoS) to look for and evaluate relevant blockchain-enabled IoT and SCM studies using the search string in Figure 1. The following stages were engaged in this article's literature search and screening: (Figure 1).
Figure 1. Procedural of the selection criteria.
Research questions formulation
This study, in particular, builds on previous work and utilizes bibliometric methodologies to address the following study questions:
RQ1: How has blockchain-based IoT in SCM evolved because of its inception?
RQ2: What nations, organizations, and writers contribute the most to SCM's scientific blockchain-based IoT research?
RQ3: Which publications in the blockchain-based IoT research in SCM are the most effective?
RQ4: What are the most prominent and most helpful funding agencies for publishing blockchain-based IoT in SCM research?
RQ5: What are some of the most hotly debated research issues and developing trends in blockchain-based IoT in SCM research?
Defining the search terms used
Before analysis, search term criteria were utilized to retrieve related literature by creating exclusion and inclusion criteria. To begin, we created a list of terms for the search criteria. To find appropriate literature, we concentrated on terms linked to the burgeoning blockchain technology-powered IoT in the SCM domain. More generic synonyms or terminology, like ‘shared ledger,’ ‘distributed ledger,’ and ‘decentralized ledger system,’ were added because of the nature of blockchain. Simultaneously, exclusion criteria were established to eliminate papers unrelated to the core issue or written in a language other than English. We also included conference papers, proceedings, and books in this study to broaden the coverage of the literature. Preliminary research in technical reports, editorials, comments, and consulting papers was omitted to guarantee quality, uniformity, and academic rigor.
Defining the database used
We utilize the WoS to gather a large amount of professional and academic literature for this investigation. There are several benefits to gathering books from WoS, including (i) WoS is the world's leading scientific citation index; (ii) it has a stringent selection procedure that results in high-quality and effective published research; (iii) WoS has earned the respect of scholars over the years by managing more than 20,300 conference proceedings, prestigious journals, and books; (iv) and it supplies investigators with some beneficial analytical attributes (Dabbagh, Sookhak, & Safa, Reference Dabbagh, Sookhak and Safa2019).
Moreover, WoS records saved to text files had complete and detailed data on author, publication year, institution, and source journal (van Nunen et al., Reference van Nunen, Li, Reniers and Ponnet2018). The search methods mostly concentrated on titles, keywords, and abstracts to investigate this subject's correlation ideas and research information. WoS yielded a total of 400 papers that were found to be genuine.
Bibliometric analysis
The bibliometric study of blockchain in SCM is presented in this section. The analysis is carried out to respond to the research questions.
Analysis of publication output
Because of the novelty and newness of blockchain in SCM, the number of publications each year ranges from 2016 to early 2021. We noticed that the academic community is starting to be interested in integrating blockchain and SCM. As presented in Figure 2, the total number of publications each year has been steadily growing since 2016, and it reached its peak in 2019 and 2020. All the publications were released from 2016 to early 2021, with 2020 being the peak year for this study. It is important to note that blockchain emerged for the first in 2008, and the literature can be traced back to 2008, and it signaled that it takes eight years for blockchain to be able to integrate with the SC, with the first literature appearing in 2016 (Christidis & Devetsikiotis, Reference Christidis and Devetsikiotis2016; Feng, Reference Feng2016).
Figure 2. The annual publication indexed by WoS from 2016 to 2021.
Since the emergence of the blockchain, introduced by Satoshi Nakamoto in 2008 (Nakamoto, Reference Nakamoto2009), blockchain technology has created hype in the financial area band. In WoS, there were around 100 subject groups for blockchain and SCM literature. Table 2 shows the top five topic areas, which include management (88 articles), engineering industrial (111 articles), computer science (77 articles), operation research management science (82 articles), and telecommunications (76 articles). The number of papers in each group mirrored the various fields' development patterns in blockchain research in SCM. In other words, as time passed, blockchain study became more multidisciplinary.
Table 2. Top five subject areas according to publications
Analysis of countries, institutions, and authors
Exploring papers' geographical and geographic distribution might be aided by examining nations and organizations. Figure 3a depicts the blockchain and SCM nation collaboration network. The node size showed how many papers were published in each nation. As the nodes expanded, more papers were released. It has been noted that blockchain has attracted worldwide attention, with experts from all over the globe contributing to it by delving further into the blockchain literature in SCM. Figures 3a and 3b illustrate the graphic representation of the nations and institutions involved in blockchain and SCM studies. As presented in Figure 3a, the largest density of contributing countries regarding the paper publication of blockchain in SCM is found in China, the USA, and England. Table 3 shows that China is the leading country with 112 published articles on the related topic. USA and England have published 87 and 56 articles, respectively.
Figure 3. The graphic representation of the nations and institutions involved in blockchain and SCM studies: (a) Mapping of the major countries; (b) Mapping of the major institutions.
Table 3. Top ten nations according to the publications
Note: TC, the total citations of a country.
Numerous scientific institutions were highly concentrated, as seen in Figure 3b, resulting in some important clusters of institutions that collaborate in the authoring of papers. Table 4 shows the top ten most prolific publishing institutions. The following organizations contributed significantly to the research: Khalifa University of Science and Technology (10 articles), Worcester Polytechnic Institute (11 articles), National Institute of Industrial Engineering Nitie (8 articles), California State University System (8 articles), and California State University Bakersfield (7 articles).
Table 4. Top ten institutions according to the publications
Moreover, Table 5 presents the top 10 most productive authors in blockchain and SCM indexed by WoS. 10 most effective authors are from USA and UEA, and the rest is from China and England.
Table 5. Top 10 most productive authors
Analysis of the most cited journal
Table 6 presents WoS indexed top 10 most cited blockchain in SCM papers. The paper titled ‘Blockchain technology and its relationship to sustainable supply chain management’ written by Saberi, Kouhizadeh (Sangeetha, Shunmugan, & Murugan, Reference Sangeetha, Shunmugan and Murugan2020) was the most cited paper, with 373 citations from the WoS database. As shown in Figure 4, the nodes of an author named Saberi are bigger than others based on the citation parameter, which is the same as Table 6.
Figure 4. The graphical map of writers who have been co-cited in blockchain and SCM studies.
Table 6. The top ten most referenced writers and their most cited papers
Analysis of the most popular venues
Table 7 illustrates the top ten most popular venues that have released journals in the blockchain and SCM domain. The result showed that IEEE Access is the most popular venue, with 43 published articles from 2016 to early 2021. Furthermore, the second place is for Sustainability, reaching 36 papers from 2016 to early 2021. In contrast, Table 8 presents the top 10 funding agencies in blockchain and SCM research indexed by WoS.
Table 7. Top 5 productive journals
Table 8. Top 10 funding agencies
With 52 papers, the National Natural Science Foundation of China (NSFC) has financed most of the 400 publications examined in this study. Furthermore, 13 articles are supported by Fundamental Research Funds for The Central Universities, while European Commission has supported nine papers. China is in the lining of competition for the total number of publications and providing funds to support the research in the blockchain and SCM domain.
Analysis of hot research topics and emerging trends
This investigation created various keyword co-occurrence networks to catch the trendy investigation and rising trend in blockchain in SCM. The VoSviewer program was used to create a knowledge area map for the term co-occurrence network, as illustrated in Figure 5a. It presented that the largest node belongs to the blockchain where the highest occurrence number is 181, with a total link strength of 850. It shows that these topics have been the hottest topic recently.
Figure 5. Knowledge domain map of a keyword co-occurrence network relevant to blockchain and SCM study: (a) network visualization map according to paper-weights; (b) overlay visualization according to paper-weights; (c) density visualization map based on article weights.
Furthermore, Figure 5b shows the overlay visualization map chosen as a more valid tool for verification of the recent trend in the academic field. The items are colored differently based on the publication year. In this study, those terms that appeared recently (the average year of publication is 2020) are more yellow. From Figure 5b, we may see that ‘supply chain transparency’, ‘agriculture’, ‘food security’, ‘covid-19’, ‘artificial intelligence’, and ‘circular economy’ are the emerging topic trends that mostly occurred in research in 2020.
Figure 5c also depicts a density visualization map demonstrating the host research themes according to paper-weights. The greater the topic's weight, the stronger the hue. Theoretical knowledge and popular research topics are primarily clustered around ‘blockchain’, ‘challenge’, ‘supply chain management’, and ‘traceability’, according to keyword research.
Conclusion and future research directions
This article provided a structured bibliometric analysis of the existing literature of Blockchain-based IoT technology for SCM security. Even though some previous studies have been discussed and reviewed this related topic, this study has not completed a bibliometric and network analysis to provide a comprehensive picture of the recent literature in the field. This initial effort maps the relationships between the most important works concerning the initial research objectives to visualize significant contributions to the field.
The study answered the first research question by examining 400 papers on the Blockchain-enabled IoT in SCM, released from 2016 to early 2021. The result presented that experts began to pay more attention to combining the blockchain and SCM concepts in 2016, and this trend has persisted through 2020. We also note that it took eight years for experts to integrate Blockchain into the SCM since Blockchain emerged in 2008, and with the first literature related to the integration of Blockchain and SCM appeared in 2016.
The geographic analysis showed that Asia, representative of China and the United States, provided the highest number of publications while other regions worldwide also contributed literature to the field. Even though China comes the first country to collect the highest total publication, the United States comes the first in terms of entire citations. Interesting to note that the highest total publication in terms of organizations is from the USA. Measuring the popularity of authors, Saberi, Kouhizadeh (Saberi et al., Reference Saberi, Kouhizadeh, Sarkis and Shen2019) is the top leading author in the analysis network, followed by Ivanov, Dolgui (Ivanov, Dolgui, & Sokolov, Reference Ivanov, Dolgui and Sokolov2019) and Zhong, Xu (Zhong et al., Reference Zhong, Xu, Chen and Huang2017).
IEEE Access and Sustainability have shown themselves as the most popular venues, based on the total number of publications, for publishing the latest advancements in the Blockchain field. However, Blockchain papers published in IEEE Access have impressed the expert community more than the Sustainability. In contrast, NSFC has supported the most number of researchers in investigating blockchain in SCM. VosViewer identified the emerging trend and patterns. Some possible directions are recommended for further investigation in this field: (1) Supply chain transparency; (2) agriculture; (3) food security; (4) COVID-19; (5) artificial intelligence; (6) circular economy.
Overall, the field of Blockchain-based IoT in SCM is growing significantly. We expect this development to grow and continue along with the community's interest in the field. Moreover, Blockchain-based IoT shows a promising concept and can play a significant role in preventing security breaches while strengthening SC connectivity. Furthermore, this paper has contributed to the Blockchain and SCM literature. This paper provided comprehensive knowledge related to the Blockchain domain and showed the current status associated with the topic area through bibliometric analysis. Second, we highlight some emerging processes by VOSviewer, which can be a guide for further investigation in this field of research.
This study opens up a number of directions for further investigation. The technical details of the highly cited papers mentioned in this study merit further investigation. Additionally, it would be intriguing to repeat the same bibliometric analysis on additional literature databases, such as Scopus, in order to see if the outcomes would be comparable to those of this study. Finally, some techniques such as machine learning (Wu et al., Reference Wu, Zheng, Chen, Zhao, Yu and Mu2021; Zhong et al., Reference Zhong, Fang, Liu, Yuan, Zhang and Lu2021), fuzzy systems (Zhang et al., Reference Zhang, Zheng, Cai, Zhang, Wang and Koh2022a), deep fusion networks (Zheng et al., Reference Zheng, Zhou, Liu, Tian, Yang and Yin2022a; Zheng & Yin, Reference Zheng and Yin2022), recursive neural net (RvNN) (Li et al., Reference Li, Xu, Chaudhuri, Yumer, Zhang and Guibas2017), few-shot learning (Zheng et al., Reference Zheng, Tian, Yang, Liu, Ding, Tian and Yin2022b), and nature-inspired algorithms (Zhang et al., Reference Zhang, Gao, Cai and Hai2022b) can help increase the efficiency of the discussed methods.
