Comprehensive Scientometric Analysis and Longitudinal SDG Mapping of Quality and Reliability Engineering International Journal

Quality and reliability are fundamental to products engineered to function both now and in the near future. Quality demonstrates how well an item serves its intended function, while reliability shows how effectively it maintains its initial quality level in varying conditions. The industry, driven by global competition, faces pressure to create novel products within shorter time frames and with higher levels of reliability and quality. However, achieving this goal necessitates the development of innovative approaches/ methodologies in quality and reliability engineering. Throughout contemporary history, shifts have occurred in the concepts of quality models, approaches, and practices, progressing from mere inspection and quality control to the implementation of quality assurance, and further evolving into the realms of quality management and quality by design.^[1] These quality movements were championed by renowned professionals such as Shewhart, Deming, Juran, Taguchi, and others, who laid the foundational principles for the quality approach adopted across various industry and business sectors. The founding editors of QREI strongly believed in the convergence of quality and reliability in engineering.^[2] Emanating from such foundational vision, statistical methods related to quality and reliability engineering research frequently feature in QREI publications serving the requirements of academia and industry alike.

The journal has established its reputation as a favourite platform for the submission of original and high-quality research emphasizing the aspects of quality and reliability in the fields of systems engineering, control engineering, electrical, mechanical, electronic and communications, software engineering, consumer products, railways, automotive, aerospace, shipboard equipment, and management. QREI is indexed in all reputed databases like Science Citation Index Expanded (SCIE) (Web of Science), Scopus (Elsevier), and SCImago, among others. The Journal Citation Report (JCR) 2021’s impact factor of QREI is 3.007. It means that articles published in QREI between 2019 and 2020 were cited at least 3.007 times in journals indexed in Web of Science. As per Scopus, QREI’s CiteScore of 4.2 in 2021 indicates that its research received, on average, 4.2 Scopus citations during 2018-2021. Furthermore, the Source Normalized Impact Factor (SNIP) for the journal is 1.511. It means that the citation rate for all QREI papers is at least 1.511 times the citation rate for all journals indexed in the same knowledge domain in Scopus. SCImago’s Journal Rank (SJR) gives QREI an h-index of 67. It means that at least 67 different articles from QREI were cited at least 67 times in Scopus on the search date. Such metrics of the journal affirm its global reputation among peers and the broader scientific fraternity. Scopus ranks QREI as 49 among 171 journals indexed in the category of Safety, Risk, Reliability, and Quality and Google Scholar identifies QREI as 12 among its 20 prominent outlets publishing on quality and reliability in 2021. Examining an individual journal using bibliometric methods provides a holistic view of the publication, presenting an analysis that goes beyond mere surface-level scrutiny. This approach can unveil the journal’s quality, developmental stage, and overall productivity.^[3] In this study, we develop a bibliometric profile of QREI, examining its publications, citations, and thematic evolution between 1985 and 2022. Bibliometrics—another name for scientometrics—is the statistical analysis of bibliographic data. It is highly recommended for establishing the historiography of academics, academic outlets, subject areas, institutions, or nations to design policies or evaluate performance.^[4–7] Numerous endeavours are evident in the literature embracing bibliometric reviews of academic outlets such as “Journal of Accounting and Public Policy”,^[4] “Journal of Advertising”,^[6] “Journal of Business Research”,^[8] “Computers and Industrial Engineering”,^[9] “European Journal of Marketing”,^[10] “Applied soft computing”,^[11] “Information Sciences”,^[12] “Nueurocomputing”,^[13] “Fuzzy Optimization and Decision Making”,^[14] “Information Systems Journal”,^[15] “Remote Sensing”,^[16] “Soft Computing”,^[17] “Fuzzy Set Theory Journals”,^[18] “Journal of Network and Computer Applications”,^[19] “Applied Mathematical Modelling”,^[20] “European Management Journal”,^[21] “Fuzzy Sets and Systems”,^[22] “IEEE Access”,^[23] “Journal of Computer Assisted Learning”,^[24] “TQM Journal”,^[25] and many more. Unfortunately, it’s a misnomer that none attempt to examine the evolution of QREI over the years. Franceschini and Maisano^[26] conducted a bibliometric survey of quality engineering-management journals, focusing on 12 such journals, including QREI. Their study primarily utilized bibliometric indicators such as the h-index and the number of citations to compare the performance of these journals. However, their analysis was limited in scope. In contrast, our current paper delves deeper into the subject by conducting an extensive examination of the evolution of QREI specifically within the timeframe of 1985-2022.

We aim to close the gap with four major objectives. Our first goal is a thorough analysis of QREI’s publications, citations, and contributions. Examining the journal’s publication and citation patterns clarifies its increasing productivity and influence. QREI authors’ contributions and affiliations are examined to learn more about the specific institutions and authors contributing significantly to the journal’s success. The precise research questions addressing this objective are:

RQ1: How are QREI’s publications and citations organized?

RQ2: Which articles are most influential in QREI, and who are its most leading contributors?

RQ3: Which journals, subject areas, and authors’ affiliations frequently cite QREI articles?

Our second objective is to introspect the collaboration patterns within QREI. Collaborations between authors from various institutional contexts are more common than those between authors from the same country or institution. The research questions emanating from this objective are:

RQ4: To what extent do the authors of QREI collaborate?

RQ5: How diverse are the worldwide collaborations of QREI authors?

Our third objective is to trace the evolution of QREI themes. Such analysis adds immense value to researchers looking for possible themes/avenues to begin or continue their academic discourse. By knowing the dominating themes, the editorial board may track the future trajectory of the journal more effectively. The research question aligned with our specific objective is:

RQ6: What themes are most prominent and influential in QREI?

Our fourth and final objective is to identify how QREI research relates to the SDGs set by the United Nations.

RQ7: How many articles of QREI are connected to SDGs?

Following is the paper’s outline: The data collection and analysis procedures are discussed in Section 2. Performance analysis (bibliometric results) of QREI publications is shown in Section 3, while QREI’s pattern of collaboration is presented in Section 4. Section 5 describes the graphical overview of influential QREI themes, prominent topics, and publication connections with SDGs, while in Section 6, we summarize our significant findings and conclude the paper with the study limitations.

Scopus was used to collect the data for this study as it provides a wide range of scientific publications that meet strict indexing criteria. For bibliometric studies, it is one of the most important scientific databases that is frequently used.^[6] Specifically, we used the “SPAR-4-SLR (Scientific Procedures and Rationales for Systematic Literature Reviews)” method developed by Paul et al.^[27] and used extensively by Raman et al.^[28,29] Figure 1 highlights the stage-wise fulfilment of the “SPAR-4-SLR” protocol.

Figure 1:
SPAR-4-SLR protocol.

The initial step, known as assembling, involves gathering of publications for examination. We used the query “Quality and Reliability Engineering International” in source titles of Scopus to gather 3400 QREI publications between 1985 and July 2022.

The second step involves the arrangement of bibliographic records using specific inclusions and exclusions criteria. The information was catalogued using publication details such as title, author, keywords, and country of origin, number of citations, and number of works cited. Further, a total of 422 publications— comprising of conference papers, retracted papers, editorials, letters, erratum, notes, conference reviews, and erroneous records—were excluded as part of our purification process.^[30–32] The conference papers are excluded due to their commonly lower scientific impact and lower robustness.^[30] It is noteworthy that impactful conference papers often evolve into journal articles, as highlighted by influential bibliometric and scientometric studies like Donthu et al.,^[31] Pattnaik et al.^[32] These considerations have led us to make a special focus on excluding conference papers, notes, editorials, etc. as done in previous bibliometric works.

Evaluation and reporting are part of the last stage assessment. The article’s evaluation section highlights the analysis approach and research constraints. MS Excel, R-Studio, VOSviewer, and Gephi are the main tools used to evaluate data and analyze trends. Ethics approval was not required as our review is mainly based on secondary data from Scopus.

A journal’s publications, citations, and impact are assessed and reported through performance analysis.^[5–7] This analysis resembles the normal participant profile found in empirical research but with more depth and evaluation. Several metrics related to publications, citations, and collaborations are included in the performance analysis.

Our first Research Question (RQ1) examines QREI’s publication and citation structure. Scopus database, Excel and R-Studio are mainly used to find publication and citation structure. QREI started publishing with four issues per year from 1985 to 1989. The number of issues reached five by 1990 and six between 1991 and 2003. Since 2004, the journal has published eight regular issues every year. Figure 2 shows the growth in the number of articles published annually and the history of publication. We analyzed QREI’s publications and citations using various quantitative metrics such as Total Publications (TP), Number of Cited Publications (NCP), Total Citations (TC), Average Citations (TC/TP), Citations per Cited Publication (C/CP), h-index, g-index, i-10 index, i-100 index, i-200 index, number of active years (NAY), and Productivity per Active Year (PAY).

Figure 2:
Annual publication in QREI.

Scientific output is measured by the Total number of Publications (TP), while the scientific impact is measured by the Total number of Citations (TC). The average impact can be measured by looking at both the total number of citations to a paper and the average number of Citations to that Paper (C/CP). The h-index and g-index are used to assess the significance and impact of a study.^[33,34] We ranked the significance of the QREI study using the i-10, i-100, and i-200 indices. These indices include QREI articles that have been cited at least 10, 100, and 200 times, respectively. An author’s activity and research output are reflected in their Number of Active Years (NAY) and Productivity per Active Year (PAY).^[7] The summarized information is presented in Table 1. The Descriptive information about RQ1 is provided in Supplementary Data (Table S1).

Table S1 shows that the Total number of Publications (TP) for QREI has grown from 30 in 1985 to 214 in 2021, and 210 articles have been published till the search date in 2022 (i.e., 26/07/2022).

To evaluate the influence of a journal and article in the scientific community, citations are a crucial indicator.^[35] The QREI articles received 39,399 citations (Table 1) between 1985 and 2022, with 85.96% (2560) articles cited at least once.

The typical number of Citations per Cited Publication (C/CP) was 9 in 1985. By 2007, it rose to 47 (the highest level ever) (Table S1). The average citations per cited article for the last three years are below 10 as the articles are comparatively new. This figure is more likely to increase over the coming years. The h-index, which measures journal influence, reached 29 in 2016, while the g-index reached 40 (i.e., 1600 citations) in 2013 and 2016.

Bifurcation of QREI’s influential publications into low, medium, and highly significant research counts to 1168, 29, and 4, respectively (Table 1). About 39.22% (1168/2976) of the articles were cited at least 10 times (i-10 index), 0.97% (29/2976) were cited at least 100 times (i-100 index), and 0.13% (4/2976) were cited at least 200 times (i-200 index). As expected, such figures indicate the growing influence and impact of the journal over the years. Conversely, the journal’s productivity—which measures its yearly Publication per Active Year (PAY)—started with 30 articles in 1985 and reached 214 by 2021 (Table S1), suggesting exponential growth.

The second research question investigates QREI’s top articles (cited at least 100 times), top authors (published at least 15 papers), and their affiliations. Scopus and Excel are mainly used in this investigation. Table S2 (Supplementary data) lists QREI’s top-cited publications. The most cited paper entitled “Multivariate statistical process control charts: An overview” published by Bersimis et al. (2007) has received the highest number of Scopus citations (445), averaging around 30 cites per year. This paper provides a comprehensive guide to the use of control charts for multivariate statistical process control. The most frequently cited QREI articles reveal a range of topics. Some of the most influential articles deal with a bootstrap control chart, fuzzy TOPSIS approach, change point method, Six Sigma, multi-response optimization, system reliability optimization, Taguchi method, Weibull proportional hazards model, artificial neural networks, Bayesian belief nets, Lean Six Sigma, and risk priority.

The most frequent and competent QREI authors between 1985 and 2022 are listed in Table S3 (Supplementary data). The table also contains details and metrics for citations of the most influential authors. Riaz M. is the most prolific contributor with 77 QREI articles, followed by Castagliola P. and Montgomery D.C. with 56 and 52 publications, respectively. The Total Citations metric (TC) suggests that Riaz M. has also been the most impactful, with 1672 citations, followed by Castagliola P. with 1364 citations, and Woodall W.H. cited 1293 times. Woodall W.H. also has the greatest average number of citations per publication, with 54. The details of the authors of the QREI papers show that the journal has succeeded in acquiring a considerable number of articles from high-ranking and globally recognized experts.

Next, we examined the authors’ affiliated nations frequently contributing to QREI. Table S4 (Supplementary data) enlists the top countries. We observe that authors associated with institutions based out of the United States, China, the United Kingdom, Taiwan, and Pakistan dominate our list with 858, 427, 264, 208, and 152 publications, respectively.

QREI authors affiliated with the United States contributed 23% of all publications, while China, the United Kingdom, Taiwan, and Pakistan contributed 11%, 7%, 6%, and 4%, respectively. In addition, authors from the United States have the highest h-, g, i-10, and i-100 indices (50, 77, 354, and 10, respectively), suggesting the greatest academic influence and impact.^[4,6,7] Surprisingly, only five nations, including the United States, Italy, the Netherlands, Greece, and Egypt, have provided at least 200 citations to QREI research (i-200). Among these five nations, authors affiliated with the United States have contributed 5 articles cited above 200 times each, while the same index for the remaining four countries is only for a single paper. Given the global diversity of the scientific fraternity in quality and reliability research, such a figure is likely to change in the near future.

Our 3^rd research question examines the leading journals, subject areas, and author affiliations that frequently cite QREI. Scopus and Excel are mainly used in this investigation. Table S5 (Supplementary data) reveals the top 20 journals and subject areas that cite QREI frequently. Apart from QREI citing itself, we find that articles published in “Reliability Engineering and System Safety”, “Computers and Industrial Engineering”, “International Journal of Advanced Manufacturing Technology”, and “International Journal of Production Research” often cite QREI articles suggesting the outward flow of QREI’s academic influence to other peer-referred outlets of international repute.

Regarding the subject areas, as highlighted in Table S5, we find that the influence of QREI is inter-disciplinary dominated by frequent citations from Engineering (14,849 times), followed by “Computer Science”, “Decision Sciences”, “Mathematics”, and “Business, Management, and Accounting” with 6380, 5229, 5049, and 3266 citations, respectively. Interestingly, leaving aside subjects such as “Health Professions”, “Pharmacology, Toxicology”, and “Pharmaceutics”, QREI has successfully gathered more than 100 Scopus citations from other disciplines as well.

Table S6 (Supplementary data) shows the top authors’ affiliations frequently citing QREI papers. Beihang University tops our list with 370 citations, followed by “Universiti Sains Malaysia”, “King Fahd University of Petroleum and Minerals”, “City University of Hong Kong”, and “King Abdulaziz University” citing at least 176 QREI articles each. Among the authors’ affiliated nations, China is at the top of our list, followed by the United States, India, Iran, and Italy, citing 3631, 1524, 820, 802, and 571 times, respectively. Further, Figure 3 reveals the nations citing at least 100 QREI articles on the search date.

Figure 3:
Top citing nations of QREI.
Note: This figure shows the nations citing at least 100 QREI documents on the search date.

Our second goal is to study the patterns of collaboration within QREI. Scops and Excel are used in finding the patterns of collaboration. To understand the evolving collaborations amongst QREI authors, a co-authorship analysis is useful.^[4] NCA (Number of Contributing Authors) refers to contributions and collaboration.^[36] Donthu et al.,^[6] and Pattnaik et al.,^[7] advise using the CI (Collaboration Index), CC (Collaboration Coefficient), SA (number of Sole-Authored), and CA (number of Co-Authored) articles are some other measures of academic collaborations. The collaborative index is one of the first indicators of collaboration level. It represents the average number of authors. Collaborative Coefficient (CC) is a metric of research collaboration that considers both the average number of authors per manuscript and the percentage of multi-authored papers.

Our 4^th research question is to understand the degrees of authorial collaboration. In addition to CI, CC, SA, and CS, Average Authors per Co-Authored Article (AACA) (mathematically calculated by (NCA-SA)/CA) can also be used to measure the degree of collaboration.^[4,6,7] To ascertain the proportions of publications with single and multiple authors, and to analyze any prevailing inclination towards collaborative research involving multiple authors, the publication records of QREI have been examined and presented in Table S7 (Supplementary data). The authorship pattern over the course of the QREI is depicted in Figure 4.

Figure 4:
Authorial distribution of QREI articles in different periods between 1985 and 2022.
Note: This figure shows the distribution of QREI articles contributed by 1, 2, 3, 4, 5, and more than 5 QREI authors between 1985 and 2022. On account of the available data for 38 years of QREI’s academic journey, the first period depicts 8 years while the remaining reflects 10 years, each.

Our study reveals that only 74 articles were single-authored during 2003-2012, which increased to 139 between 2013 and 2022. However, this figure is low during 1985-1992 and 1993-2002. It is also inferred that since 2003 the bulk of QREI publications has been by two to four authors suggesting frequent collaborations, which may indicate diversity in intellectual discourse. Further, as Table S7 (Supplementary data) appears, the percentage of sole-authored articles decreased from 48% during 1985-1992 to 9% between 2013 and 2022, while the percentage of co-authored articles increased from 52% during 1985-1992 to 91% between 2013 and 2022. The table also shows an increase in CI from 0.81 (1985-1992) to 2.04 (2013-2022), CC from 0.42 (1985-1992) to 0.67 (2013-2022), and AACA from 2.55 (1995-1992) to 3.23 (2013-2022). Thus, our empirical evidence supports the claims of Raman et al.^[23] and Baker et al.^[4] that increased specialization and methodological complexity are contribute to an increase in authorial collaborations across scientific domains.

Our 5^th research question investigates the range of global collaborations among QREI authors. Based on the contributing authors’ countries of origin, Table S8 (Supplementary data) depicts the ranking of the top co-authored papers at QREI. It shows that authors from Pakistan and Saudi Arabia work together most frequently, followed by those from the United States and Iran, Taiwan, Korea, and India. Overall, authors associated with the United States and China employ most commonly, indicating that these nations are the collaborating hearts of QREI publications.

The impact of international collaboration in terms of citations shows that close to 30% of publications have international collaborations, with a high citation impact of 15.9 citations per publication (Table 2).

Our 6^th research question explores the important research themes of QREI and maps their progression. This research relies on information gathered from the titles and abstracts of 2,978 papers published in QREI. We didn’t include generic stop words like “a”, “the”, “is”, and “are” or more specific ones like “article”, “paper”, “research”, and “study”. A co-occurrence study of keywords^[37] is used to investigate the convergence of subjects into themes in QREI, where “keywords” refer to the “bigram and trigram terms or topics” revealed by a machine learning n-gram analysis.^[38] Börner et al.^[39] and Andersen^[40] suggest that frequent overlaps between keywords (topics) show thematic convergence, which makes it possible to think about subject areas or functional departments in a research field. We have compiled a variety of bibliometric data using the tools MS-Excel, R, VOSviewer, and Gephi to illuminate the depth of research in QREI and the underlying diversity of topics. Andersen^[40] has noted that the number of citations of a scientific paper shows how important that paper is. Therefore, we used VOSviewer and Gephi to calculate how often the corresponding QREI article on each topic (keyword—bigram or trigram term) was cited on average.^[41,42] The Average Publication Year (APY) was also composed as they correspond to the “hotness” (most recent) or “coldness” (least recent) of themes.^[43] Overall, the analysis revealed 296 topics under 10 different clusters. In a co-occurrence analysis, the bigram and trigram words were used to show how the same ideas recur and form thematic clusters.^[7] The first cluster is the largest, with 112 topics, followed by cluster 2, with 67 topics, cluster 3 with 29 topics, cluster 4 with 24 topics, cluster 6 with 15 topics, cluster 7 with 15 topics, cluster 5 with 13 topics, cluster 8 with 11 topics, cluster 9 with 5 topics, and cluster 10 with 5 topics.

The first cluster is the largest among all, with 112 topics related to reliability and risk analysis. Prominent themes discussed in the cluster are reliability analysis, system reliability, software reliability, reliability model, reliability prediction, reliability assessment, reliability evaluation, product reliability, system failure, reliability growth model, reliability improvement, risk factors, risk analysis, risk assessment, Weibull distribution, Bayesian network, Bayesian inference, competing risks, accelerated degradation, Wiener process, Fault Tree Analysis, Hazard rate, repairable system, likelihood estimation, exponential distribution, accelerated life test, and failure rate among others. “Reliability analysis” leads the cluster with the highest occurrences in 152 QREI articles. Based on average citations, “reliability optimization” tops our list with 39 citations per paper. Based on APY, the most recent topic from the cluster is “progressive hybrid censoring”, with an APY score of 2021.0. Huang and Askin^[44] and Levitin and Lisnianski^[45] feature as the top-cited articles on reliability analysis and reliability optimization in our list, cited 118 and 183 times, respectively; and we find Alam et al.^[46] as the most recent article on progressive hybrid censoring.

The second cluster contains 67 topics related to quality modelling. Prominent themes discussed in the cluster are quality characteristics, quality control, quality assurance, quality management, quality loss, multiple quality characteristics, total quality management, off-line quality control, process capability, manufacturing process, process performance, process yield, process improvement, and process variance. Some of the prominent research methods highlighted in the cluster include such terms as genetic algorithm, neural network, support vector machine, linear models, logistic regression, and Taguchi method, among others. “Quality control” leads the cluster with the highest occurrences in 113 QREI articles. Based on average citations, “Taguchi method” tops our list with 28 citations per paper. Based on APY, the most recent methodological topic from the cluster is “support vector regression”, with an APY score of 2017.8. Williams et al.^[47] and Tong and Su^[48] feature as the top-cited articles on quality control and Taguchi method in our list, cited 230 and 175 times, respectively, while Gu et al.^[49] article is the most recent that applies support vector regression.

The third cluster contains 29 topics related to process control modelling. Prominent themes discussed in the cluster are process control, statistical process, linear profiles, nonlinear profile, likelihood ratio, generalized likelihood, regression model, linear regression, profile monitoring, statistical monitoring, simultaneous monitoring, Gaussian process, and profile data, among others. “Process control” leads the cluster with the highest occurrences in 231 QREI articles. Based on average citations, “profile data” tops our list with 37 citations per paper. Based on APY, the most recent topic from the cluster is “simultaneous monitoring”, with an APY score of 2018.5. Bersimis et al.^[50] and Mahmoud et al.^[51] feature as the top-cited articles on process control and profile data in our list, cited 445 and 250 times, respectively, while Rahimi et al.^[52] article is the most recent on simultaneous monitoring.

The fourth cluster contains 20 topics related to process monitoring. Prominent themes discussed in the cluster are process monitoring, weighted moving average, Exponentially Weighted Moving Average (EWMA) control chart, process dispersion, efficient monitoring, synthetic control chart, and triple exponentially weighted moving average. “Weighted moving average” leads the cluster with the highest occurrences in 291 QREI articles. Based on average citations, the “synthetic control chart” tops our list with 24 citations per paper. Based on APY, the most recent topic from the cluster is “triple exponentially weighted moving average”, with an APY score of 2021.3. Abbas et al.^[53] and Machado et al.^[54] feature as the top-cited articles on weighted moving average and synthetic control chart in our list cited 138 and 43 times, respectively, while Malela‐Majika et al.^[55] article is the most recent on triple exponentially weighted moving average control chart in our list.

The fifth cluster contains 12 topics related to control chart(s). Prominent themes discussed in this cluster are control chart(s), statistical control, auto correlated processes, monitoring time, Poisson processes, and negative binomial. “Control chart(s)” leads the cluster with the highest occurrences in 778 QREI articles. Based on average citations, “Statistical control” tops our list with 20 citations per paper. Based on APY, the most recent topic from the cluster is “Monitoring time”, with an APY score of 2019.7. Bersimis et al.^[50] and Abbas et al.^[53] feature as the top-cited articles on a control chart(s) and statistical control in our list, cited 445 and 138 times, respectively, while Zhang et al.^[56] article is the most recent on monitoring time between events in our list. This article refines the lower side of the EWMA control chart by using the strength of Time Between adverse Event (TBE) observations to determine the trend of the decrease in the mean TBE value.

Pattnaik et al.^[7] highlighted that an article may be associated with multiple topics. Here, the articles of Bersimis et al.^[50] and Abbas et al.^[53] are also associated with multiple topics. We can see that article of Bersimis et al.^[50] was a part of cluster 3 and is also a part of cluster 5. In the same way, the article of Abbas et al.,^[53] which was a part of cluster 4, also features in cluster 5.

The sixth cluster contains 14 topics related to CUSUM. Prominent themes discussed in the cluster are CUSUM, multivariate EWMA, multivariate CUSUM, Shewhart control, and adaptive multivariate EWMA, among others. “CUSUM” leads the cluster with the highest occurrences in 200 QREI articles. Based on average citations, “multivariate EWMA” tops our list with 12 citations per paper. Based on APY, the most recent topic from the cluster is “adaptive multivariate EWMA”, with an APY score of 2020.2. Zhang et al.^[57] and Testik et al.^[58] feature as the top-cited articles on CUSUM and multivariate EWMA with 91 and 48 citations, respectively, while Haq and Khoo^[59] article is the most recent on adaptive multivariate EWMA.

The seventh cluster contains 15 topics related to measurement error and process quality. Prominent themes discussed in the cluster are measurement error, process quality, Markov chain, run length, average run length, compositional data, and multivariate coefficient. “Measurement error” leads to the cluster with the highest occurrences in 64 QREI articles. Based on average citations, “process quality” tops our list with 29 citations per paper. Based on APY, the most recent topic from the cluster is “compositional data”, with an APY score of 2019.6. Hu et al.^[60] and Williams et al.^[47] feature as the top-cited articles on measurement error and process quality in our list, cited 49 and 230 times, respectively, while Imran et al.^[61] (2022) article is the most recent on compositional data.

The eighth cluster contains 10 topics related to sample size, shape, and scheme in quality and reliability research. Prominent themes discussed in the cluster are sample size, shape parameter, sampling scheme, Weibull shape, and Double Sampling (DS). “Sample size” leads to the cluster with the highest occurrences in 189 QREI articles. Based on average citations, “double sampling” tops our list with 19 citations per paper. Based on APY, the most recent topic from the cluster is the “sampling scheme”, with an APY score of 2016.0. Zhang et al.^[57] and He and Grigoryan^[62] feature as the top-cited articles on sample size and double sampling in our list, cited 91 and 58 times, respectively, while Hyder et al.^[63] article is the most recent on the sampling scheme.

The ninth cluster contains 5 topics related to adaptive EWMA. Prominent themes discussed in the cluster are adaptive EWMA, Monte Carlo, and Real data sets. “Real data sets” leads the cluster with the highest occurrences in 26 QREI articles. Based on average citations, “adaptive EWMA” tops our list with 20 citations per paper. Based on APY, the most recent topic from the cluster is “adaptive EWMA”, with an APY score of 2019.1. Riaz et al.^[64] and Aly et al.^[65] feature as the top-cited articles on real data sets and adaptive EWMA in our list, with 52 and 63 citations, respectively, while Sarwar et al.^[66] article is the most recent on the adaptive EWMA.

The tenth cluster contains 5 topics related to anomaly detection. Prominent themes discussed in the cluster are anomaly detection, intrusion detection, and social networks. “Anomaly detection” leads to the cluster with the highest occurrences in 9 QREI articles. Based on average citations, “intrusion detection” tops our list with 38 citations per paper. Based on APY, the most recent topic from the cluster is “social networks”, with an APY score of 2019.0. Ye and Chen^[67] feature as the top-cited articles on anomaly and intrusion detection in our list cited 172. Hazrati-Marangaloo and Noorossana^[68] article is the most recent on social networks.

This section presents the temporal evolution of QREI themes during five APY periods.

APY 1985.0 and 2000.0: Figure S1 (Supplementary data) demonstrates the dominant topics in QREI between APY 1985.0 and 2000.0. Highly impactful terms include hazard rate curve, hazard modelling, reliability prediction, total quality management, and Taguchi method.
APY 2000.1 and 2005.0: Figure S2 (Supplementary data) shows the themes that became popular in QREI between APY 2000.1 and 2005.0. Highly impactful terms include offline quality control, quality engineering, product design, proportional hazards, reliability improvement, and quality improvement.
APY 2005.1 and 2010.0: Figure S3 (Supplementary data) suggests the themes that gained prominence in QREI between APY 2005.1 and 2010.0. Highly impactful terms include reliability optimization, fault tree, failure mode, process quality, manufacturing quality, quality control, statistical control, and intrusion detection.
APY 2010.1 and 2015.0: Figure S4 (Supplementary data) reveals the themes that gained prominence in QREI with APY between 2010.1 and 2015.0. Highly impactful terms include reliability estimation, maintenance management, multiresponse optimization, multiple quality characteristics, simple linear regression, statistical monitoring, control chart, cumulative sum control, sample size, double sampling, Weibull shape, process parameters, and synthetic control.
APY 2015.1 and 2022.0: Figure S5 (Supplementary data) reveals the popular and influential themes on QREI with APY between 2015.1 and 2022.0 such as multivariate CUSUM, multivariate EWMA, adaptive EWMA, EWMA control, risk factors, profile data, anomaly detection, and condition-based maintenance. In order to propose future studies or contributions to the journal, researchers could examine the current topics and consider those that arise from the gaps indicated by the missing links in the journal’s thematic maps.

Figure S1:
Influential topics published in QREI with APY between 1985.0 and 2000.0.
Notes: Nodes = topic represented by bigram or trigram. Color of nodes=thematic cluster of nodes where, cluster 1 (purple), cluster 2 (green), cluster 3 (blue), cluster 4 (black), cluster 5 (orange), cluster 6 (red), cluster 7 (deep green), cluster 8 (suave), cluster 9 (off grey), and cluster 10 (grey). Size of nodes=citations garnered by a topic. Link=co-occurrence between nodes.

Figure S2:
Influential topics published in QREI with APY between 2000.1 and 2005.0.
Notes: Nodes=topic represented by bigram or trigram. Color of nodes=thematic cluster of nodes where, cluster 1 (purple), cluster 2 (green), cluster 3 (blue), cluster 4 (black), cluster 5 (orange), cluster 6 (red), cluster 7 (deep green), cluster 8 (suave), cluster 9 (off grey), and cluster 10 (grey). Size of nodes=citations garnered by a topic. Link=co-occurrence between nodes.

Figure S3:
Influential topics published in QREI with APY between 2005.1 and 2010.0.
Notes: Nodes=topic represented by bigram or trigram. Color of nodes=thematic cluster of nodes where, cluster 1 (purple), cluster 2 (green), cluster 3 (blue), cluster 4 (black), cluster 5 (orange), cluster 6 (red), cluster 7 (deep green), cluster 8 (suave), cluster 9 (off grey), and cluster 10 (grey). Size of nodes=citations garnered by a topic. Link=co-occurrence between nodes.

Figure S4:
Influential topics published in QREI with APY between 2010.1 and 2015.0.
Notes: Nodes=topic represented by bigram or trigram. Color of nodes=thematic cluster of nodes where, cluster 1 (purple), cluster 2 (green), cluster 3 (blue), cluster 4 (black), cluster 5 (orange), cluster 6 (red), cluster 7 (deep green), cluster 8 (suave), cluster 9 (off grey), and cluster 10 (grey). Size of nodes=citations garnered by a topic. Link=co-occurrence between nodes.

Figure S5:
Influential topics published in QREI with APY between 2015.1 and 2022.0.
Notes: Nodes=topic represented by bigram or trigram. Color of nodes=thematic cluster of nodes where, cluster 1 (purple), cluster 2 (green), cluster 3 (blue), cluster 4 (black), cluster 5 (orange), cluster 6 (red), cluster 7 (deep green), cluster 8 (suave), cluster 9 (off grey), and cluster 10 (grey). Size of nodes=citations garnered by a topic. Link=co-occurrence between nodes.

We have also focused on the prominence percentile to evaluate the level of interest in or exposure to this study. The citation counts, views, and average CiteScore are the three indications that Scival uses to determine a topic’s momentum. We have uploaded the entire data of QREI in Scival to get prominent research topics. Eight study topics listed in Table 3 are ranked by prominence percentile. These study topics have high percentiles of visibility, ranging from 99.71 to 97.21. The top three topics with high prominence percentile are i) Useful Life; Health Care Management; Rolling Bearing (99.71), ii) Total Quality Management; Process Monitoring; Six Sigma (99.02), and iii) Fidelity; Surrogate Model; Metamodelling (98.67).

Our last and final research question is about mapping the articles of QREI with SDGs. Scopus and SciVal are mainly used in mapping the articles with SDGs. The SDGs, also known as the Global Goals, was established by the United Nations in 2015. These goals have 17 objectives that must be achieved by 2030, and its progress is measured by 169 indicators. There have been several research studies published that relate how publications map to various SDGs.^[28,29,69] Here, Elsevier SDG Mapping Initiative^[70] has been used for mapping the QREI papers with SDG.

Our choice of the Elsevier SDG Mapping Initiative is based on its direct integration within the search criteria of the Scopus database through its Science-Metrix group. The initiative employs 17 distinct SDG queries to map publications to the corresponding 17 SDGs. These queries have been meticulously devised based on the unique targets and sub-targets of each SDG. Further refinement for precision is achieved through thorough review and feedback from experts and academics. These queries were then supplemented by a machine learning model, ensuring the precision remained above 80%. The Scopus database facilitates the research process by providing pre-set search queries for each SDG.^[71]

According to Elsevier SDG Mapping, 256 articles in “QREI” map to various SDGs. Table 4 enlists the SDGs that have the most articles mapped. Industry, innovation, and infrastructure (SDG9), affordable and clean energy (SDG7), and good health and well-being (SDG3) have the most mapped publications in QREI.

The top three articles mapped to these SDGs are listed in Table S9 (Supplementary data). According to citations, SDG9 is the most mapped, with 2210 citations. The top-cited article on SDG9, by Gijo and Antony,^[72] discusses how a project in an Indian hospital’s outpatient department was able to reduce patient wait times with a process-innovation and improved value-chain management. The top-cited article on SDG7, by Sari et al.,^[73] proposes a reliability estimation model for LED lighting systems leading to energy efficiency and reduced energy consumption. Conversely, the top-cited article on SDG3 by Han et al.^[74] discusses the use of control chart techniques in public health and public health surveillance to detect increases in the prevalence of diseases.

This article presents analytical results of publication and citation patterns, authorship structure, collaboration patterns, and thematic and temporal analysis of topics published in the QREI journal. This study delivers important conclusions and consequences for QREI’s readers and stakeholders using performance analysis, text mining (machine learning n-gram analysis), and science mapping (co-occurrence analysis).

Firstly, QREI has become a leading publication hub, regularly ranking among the best international journals in the field of quality and reliability engineering for a variety of well-known benchmark metrics (e.g., Scopus CiteScore, Scimago Journal Rank, Web of Science: SCI impact factor and Google Scholar). The journal has published almost seven times as much in recent years as it did initially. QREI editors and editorial board members are encouraged to curate editorials to convey the themes, novelty, and rigour they expect from prospective and experienced journal contributors. Interestingly, the journal’s intelligentsia covers diversified topics from twenty different disciplines. However, engineering, computer science, and decision science discourse has dominated QREI discussions over the years.

Second, the importance of collaboration: There has been an increasing trend of multi-authored papers and the proportion of papers involving international collaboration. Initially (1985-1992), 52% of QREI publications were multi-authored, which is now increased to 91% (2013-2022). While single-authored articles are reduced to 9% (2013-2022) from 48% (1985-1992). The top three research collaborative countries are Pakistan-Saudi Arabia, United States-Iran, and United States-Taiwan.

Third, QREI has contributed to a wide range of topics. Our analysis reveals 296 topics under 10 different clusters, namely reliability and risk analysis, quality modelling, process control modelling, process monitoring, control chart(s) based monitoring, CUSUM (cumulative sum control chart), measurement error and process quality, sample size, shape, and scheme, adaptive EWMA, and anomaly detection. The most recent trending topics include triple exponentially weighted moving average (APY 2021.3), progressively hybrid censoring (APY 2021), adaptive multivariate EWMA (APY 2020.2), adaptive EWMA (2019.1), multivariate CUSUM (2018.6), Wiener process (2018.5), risk analysis (2017.8) and Bayesian network (2017.3).

Fourth, QREI contribution to SDG-related articles: Our analysis revealed 256 articles given the focus areas connected to the SDGs. The most contributed and cited articles are synchronized with SDG9 (on industry, innovation, and infrastructure).

Another encouraging indicator for this journal is its increase in interdisciplinary research papers with multiple authors.

Nevertheless, despite the contributions of this retrospective survey of QREI, there are several limitations. First, this study remains limited to the accuracy and completeness of the bibliometric data of the journal in Scopus. Best efforts have been undertaken to ensure that the data are clean and accurate (e.g., correcting erroneous entries and text mining using machine learning instead of manual coding). Second, the quality and reliability engineering review here is limited to the insights from QREI and remains limited to the journal’s performance. Thus, future retrospectives may survey a wide range of quality and reliability engineering journals and provide a more comprehensive overview of quality and reliability engineering outlets.