The operational excellence research landscape in Africa: a scoping review

To remain competitive, organizations across the globe are continuously working toward ensuring that their operations are made better, faster and cheaper. This is especially true in an ever-changing and often uncertain economy. These efforts have, in many major organizations, been translated into operational excellence (OpEx) initiatives (Russell, 2009). The roots of OpEx can be traced back to the Industrial Revolution and Scientific Management, and it has steadily evolved from there, also incorporating the Human Resources movement over time (Lyskova, 2020; Hirano and Takeuchi, 2022).

Over the years, OpEx has become a more common approach that organizations are using worldwide (Russell, 2009), also extending into the realms of Industry 4.0 (D’Orazio et al., 2020; Antony et al., 2022). This scoping review is focused on establishing where and to what extent integrated OpEx practices and research are being researched and used on the African continent.

Despite being the world’s second most populous continent, it remains underrepresented in science and scientific literature (Okeke et al., 2017; Salager-Meyer, 2008; King, 2004). In fact, a steady decline in Africa’s global share of published research articles, along with a persistent lack of international impact, was highlighted by Tijssen (2007). In a study on the scientific impact of countries, King (2004) found that 31 of 191 nations accounted for 98% of citations, with South Africa being the only African country on the list, ranked 29th. This article aims to identify, and then map, what scientific contributions have been made on OpEx in Africa by approaching the research from the perspectives of “what,” “where” and “how.” The research questions (RQs) are therefore:

The purpose of insight into the use of and research in OpEx in Africa will assist in understanding the state of the continent’s development in OpEx research and could enable the identification of research gaps, comparative studies, facilitate learning and implementation and identify opportunities for collaboration. Some practical and theoretical implications of this scoping review are:

• contributing to existing scoping review data on research in different fields in Africa for use in research funding and policy decision-making;

• providing a baseline for further such studies, which could explore the topic in more depth or from a different, comparative angle;

• providing a time-efficient overview source for OpEx researchers focusing on OpEx in Africa;

• this scoping review is especially useful in testing hypotheses on research in Africa, but also to identify research gaps in OpEx; and

• providing a database for researchers from inside and outside the continent looking for collaboration opportunities.

As the vast majority (more than 80%) of the articles were case studies of OpEx implementation, this scoping review can also serve as a reference guide for practitioners to find cases with similarities to their project context. The body of literature screened (353 articles) and reviewed (101 articles) for this paper found no scoping reviews conducted and published on this topic, making this a unique overview of the published OpEx literature and confirms the scoping review approach as an appropriate method with which to explore, chart as it were, the uncharted field of OpEx research in Africa.

The remainder of this scoping review will overview literature as it applies to both OpEx and Africa, discuss the methodology used to answer the RQs and an analysis and discussion of the data’s main findings. Finally, the conclusion will discuss all the main findings of the paper and provide further recommendations.

The purpose of this literature review is to ground this research in theory. As this study investigates the overlap between OpEx and Africa, these two spheres were investigated and reviewed here.

A reading of the OpEx literature can be quite confusing as the term is used in at least two different distinct ways: a generic interpretation of the term as an operations function that is truly excellent and a more specific interpretation of the term that refers to the continuous improvement of operations toward excellence using various tools, concepts, techniques and principles developed by companies, with Toyota being the most notable.

The generic interpretation of the term gained popularity in the writings of Peters and Waterman (1984) who studied the best companies and identified the traits that resulted in excellence, with the McKinsey 7S framework, which married western and eastern management practices, with strategy, systems and structure borrowed from the west, and style, staff, skills and shared values borrowed from the east (Found et al., 2018). The generic interpretation of the term was defined by Treacy and Wiersema (1995) as “the strategy for organizations striving to deliver a combination of quality, price and ease of purchase, and service, that no other organization in their market, or industry, can match.”

The more specific interpretation of the term is closely linked to the lean movement, originating in the Toyota Motor Corporation under the leadership of Taiichi Ohno and Shigeo Shingo (Womack et al., 2007). Considered as the more contemporary interpretation of OpEx (Found et al., 2018), the latter interpretation of OpEx was used in this study.

Many of the concepts, principles and techniques incorporated into what became known as the Toyota Production System (TPS) had had their origin in the Industrial Revolution, Scientific Management and the influence of scholars such as Juran, Shewhart and Deming (Peters and Waterman, 1984). Juran (2003) describes OpEx as a business philosophy that prioritizes customer needs, a positive and empowered workforce by emphasizing problem-solving, teamwork and leadership that enables continuous improvement. According to Dinis-Carvalho and Macedo (2021), Shingo packaged the teachings of Juran into a model consisting of ten core principles of OpEx, grouped into three dimensions:

1. Cultural: respecting each individual and leading with humility.

2. Continuous improvement: seeking perfection, adopting scientific thinking, focusing on processes, ensuring quality at the source and improving flow and pull.

3. Enterprise alignment: thinking systematically, creating continuity of purpose and creating value for the customer.

The discussion so far gives background to why OpEx, as well as lean, faces the criticism of being poorly defined and its research being practice-led (Found et al., 2018). Nevertheless, the popularity and longevity of the OpEx evolutionary phases suggests that it is widely seen as a worthwhile contribution to the field of business improvement and management.

Over the years, the OpEx values have been developed into, or have guided, the establishment of numerous OpEx approaches aimed at transforming processes across different industries into more streamlined and capable processes (Plenert, 2018). Some of the popular OpEx approaches and techniques available to organizations today are: lean management/TPS, Six Sigma, total quality management (TQM) (Jalundhwala and Londhe, 2023), Kaizen, just-in-time (JIT) (Bhamu and Singh Sangwan, 2014), business process reengineering (BPR) (Anand and Kodali, 2009), total productive maintenance (TPM) (Gupta et al., 2015), Lean Six Sigma (Francescatto et al., 2023), ISO 9000/1 (Sfreddo et al., 2021), theory of constraints (TOC) (Mabin and Balderstone, 2020).

Many more OpEx tools and techniques exist in addition to those listed here, such as standardization, 5S, kanban, Andon, Toyota Kata, Poka Yoke, Single-Minute Exchange of Dies, to name just a few. These OpEx techniques are finite in their scope and focused on addressing a specific enabling OpEx outcome or solving a specific problem. Due to their narrow focus, they lie at a different conceptual level than those OpEx approaches listed above. These approaches integrate a number of the more specific and focused tools and techniques. For example, TPM incorporates 5S, Jidoka and other maintenance-focused techniques, and the TPS incorporates 5S, standardization, JIT, Jidoka, etc. To focus on the scope of this study, it was decided to focus on the more integrated OpEx approaches, which then encapsulate the wide variety of OpEx techniques, specifically focusing on the ten listed above. In support of this reasoning, Carvalho et al. (2017) argued that the term OpEx should be associated with a framework that incorporates tools that enable organizations to effect change.

The preliminary literature review screened the literature using the search terms “OpEx” and “Africa.” A list was then made of all the OpEx approaches mentioned, after which the scoping decision described above was made to ensure a degree of conceptual consistency.

Two of the judgment calls made by the authors during this scoping process could be deemed controversial and warrant debate: the inclusion of JIT and the interchangeable use of TPS and lean management. Both of these judgment calls will be discussed here.

JIT was the only OpEx approach that did not seem quite as holistic as some of the other approaches listed here but was also not a discrete tool or technique. To establish JIT effectively requires 5S, kanban, optimized inventory, SMED, etc. Due to the fact that it encapsulates a few OpEx concepts, tools, techniques, etc., it was decided to include it as an integrated approach.

The other pillar of the TPS, Jidoka, was not included as one of the ten integrated approaches being studied because it is not as widely disseminated as JIT, and as a principle has been incorporated into TQM, and ISO9001, although purists may argue that it has been diluted as a result.

Whether the authors agree or not with how researchers approached the concept of JIT, the aim of the scoping review was to map existing literature and not to correct it. There is a significant amount of ambiguity and confusion surrounding the definition of many OpEx approaches, with JIT being described as a tool, technique, approach, principle and philosophy in just two articles that passed peer review (Mukwakungu et al., 2019; Wyk and Naidoo, 2016). In the case studies screened, JIT required the implementation of various OpEx concepts to be achieved, which convinced the authors that it should be included as one of the broader encompassing OpEx concepts.

Grouping TPS and lean management also did not feel quite correct. The TPS, a precursor to lean management, was developed by Taiichi Ohno of the Toyota Motor Corporation in the 1950s (Gao and Low, 2014). The approach of the TPS was then popularized through the lean manufacturing interpretation by Womack and Jones (1997) and Womack et al. (2007). Later, lean manufacturing became lean management as it was adopted successfully into settings other than manufacturing.

Considering the TPS to be a standalone OpEx approach would greatly reduce it his presence in the literature when it comes to case studies in Africa. However, the TPS approach is still present in the lean management case studies, and it did not feel correct to the authors to say that TPS is basically absent from the African continent, when in fact, it has a significant legacy in the implementation of lean management.

There is a lot of work to be done around cleaning up and clarifying definitions within the sphere of OpEx as even the definition of OpEx does not have consensus in the literature. It was out of scope of this scoping review to do this clarification as the aim of the review was to gauge the OpEx research landscape on the African continent.

Africa is the continent with the second largest population in the world, estimated to be almost 1.4 billion people in 2024 and accounts for almost one-fifth of the world population. The median age in Africa is around 19 years, and the only region with a predicted steady growth throughout the 21st century. The 15 most populous countries in Africa are ranked from most to least populous, Nigeria, Ethiopia, Egypt, Democratic Republic of the Congo, Tanzania, South Africa, Kenya, Sudan, Uganda, Algeria, Morocco, Angola, Mozambique, Ghana and Madagascar (UNDESA, 2019).

According to the United Nations Statistics Division, the geoscheme of the African continent is divided into five main regions, namely, Northern, Central, Southern, Eastern and Western Africa (Turay, 2022). Figure 1 presents a graphical layout of the 57 African countries, grouped into the five regions. In terms of the number of countries per region, Eastern Africa comprises 19 countries, making it the largest in Africa. The second largest region is Western Africa, consisting of 17 countries. Central, Northern and Southern Africa have nine, seven and five countries, respectively.

As the second largest continent, Africa is well known for its vast riches in minerals, for example:

• Around 90% of global platinum and palladium reserves are located in South Africa.

• Around 70% of the world’s cobalt production comes from the Democratic Republic of Congo.

• Around 70% of the world’s phosphate reserves are located in Morocco and Western Sahara.

Despite its abundance of resources and large population, Africa has some of the poorest communities with the highest levels of poverty worldwide. Additionally, its economies are highly dependent on the production and export of minerals, with mining accounting for more than 50% of the export revenue of at least one-third of these countries (Jessell et al., 2018), even though this characteristic is improving as Africa makes strides in its development (Cloete et al., 2022). This must be considered when considering the gross domestic product (GDP) statistics of the continent as a high GDP might not necessarily correlate with a versatile industry in which to practice OpEx. Figure 2 provides an indication of each African countries’ GDP in the year 2024 relative to the rest of the globe (IMF, 2024).

The countries with the highest nominal GDP in Africa are, in order of highest to lowest GDP, South Africa, Egypt, Algeria, Nigeria, Morocco, Ethiopia, Kenya and with Tanzania and Ghana in tenth and 11th places, respectively, and Zimbabwe, featured later in this article, in the 17th place.

As mentioned in Section 1, research on and from Africa is underrepresented in the literature (Tijssen, 2007). Even though Africa experience a decline in research output, in the 1980s and 1990s, recent decades have seen an increase in inter- and intra-continental research collaboration (Tijssen and Winnink, 2022). Tijssen and Winnink (2022) also identified a dependence on international research funding, and collaboration with researchers from more developed countries in their review of research excellence on the continent, which can be understood in the background of the relative poverty of most countries on the continent, as shown in Figure 2. Cloete et al. (2018) list the challenges facing African research universities as: access to funding for scientific research, appropriate science policy initiatives, effective deployment of incentive systems to promote international-level performance and having access to state-of-the-art technical infrastructure and research facilities.

Tijssen and Winnink (2022), however, highlight the research excellence that is prevalent on the African continent and argue that, exactly due to the listed challenges, the research efforts of high-impact African researchers should be supported through collaborations with researchers in the Global North. This paper aims to be a catalyst for such collaboration, especially in the OpEx research landscape.

Scoping reviews are deemed appropriate to identify knowledge gaps, scope and map a body of literature, clarify concepts and to investigate research conduct (Peters et al., 2020; Tricco et al., 2018). It also has proven utility in the evaluation of emerging evidence as well as the initial phase of research and development (Peterson et al., 2017). As no publication was found that gave an overview of what OpEx research has been published that focuses specifically on the African continent, the scoping review methodology was selected as an appropriate approach to answer the RQs posed in this review.

The review followed the systematic eight-step process presented by Okoli (2015) and referenced the PRISMA-SCR checklist during the writing of the article to ensure that the right topics and detail are covered, and sufficient evidence is presented of how the methodology was systematically followed.

As discussed in Section 1, the purpose of this research is to understand the state of the continent’s development in OpEx research, to enable the identification of research gaps, be a catalyst for comparative studies, facilitate learning and implementation and identify opportunities for collaboration. This was done by identifying, then mapping, the OpEx research landscape in Africa by approaching the research from the perspectives of “what,” “where” and “how.” The RQs are therefore:

• What: What OpEx research has been published in Africa?

• Where: Which countries and regions are the most active in OpEx research on the continent?

• How: Which OpEx approaches are the most prevalent in the research?

The preliminary review used the search terms “OpEx” + “Africa” and “Operations/al Excellence” + “Africa” to gain a broad insight into the field and to how OpEx research is being published. After the preliminary literature review, the authors agreed on which search terms to use and what search protocol to follow, as well as which inclusion and exclusion criteria to use.

As discussed in Section 2.1, the scope was limited to integrated OpEx approaches – those OpEx approaches that use various OpEx tools and techniques in an integrated way, but the tools themselves were not included as search terms. This was due to the substantial number of tools available and the different conceptual plain that these tools lie on as opposed to the higher-level, integrated approaches such as TQM or TPS. The following search terms were thus used:

• “Lean” + “Africa”

• “Toyota Production System” + “Africa”

• “Six Sigma” + “Africa”

• “Total Quality Management” + “Africa”

• “Kaizen” + “Africa”

• “Just-In-Time” + “Africa”

• “Business Process Reengineering” + “Africa”

• “Total Productive Maintenance” + “Africa”

• “Lean Six Sigma” + “Africa”

• “ISO 9000/1” + “Africa”

• “Theory of Constraints” + “Africa”

The Google Scholar relevance algorithm was used initially for its ability to search, and rank, a wide variety of databases. For each of the 11 search terms listed in Section 3.3, the first ten pages of search results were screened for articles that apply to the African context and relate to one of the 11 OpEx approaches identified to be within scope. This screening of 1,100 search results delivered a sample of 353 relevant articles.

All of the remaining recorded articles were placed within two matrices. The first matrix assigned the article to its respective African country and OpEx technique, while the second matrix assigned it to the industry in which it was detected and again, its respective technique.

After screening through the sample of articles, which contained mostly case studies, many without a clear or novel research contribution, the authors decided to include only those articles that had been peer reviewed and published in either the Scopus or Web of Science catalogs. This would ensure that the research being mapped was research that clearly contributes to the existing body of knowledge. Following this screening, 101 articles were left in the sample. To avoid exceeding the word count guidelines of this journal, the full list of analyzed articles, along with their references, is given in Supplementary material.

Descriptive statistical analysis was used to synthesize and map the data captured in the matrices mentioned in Section 3.6. The visualized data is presented in Section 4 of this article, which is the resulting scoping review.

During the writing of the scoping review, the PRISMA-SCR checklist was used to ensure that the relevant topics and details are covered, and sufficient evidence was provided within the article or its supplementary material where the word count limit did not allow its inclusion.

This section presents the analysis of the collected data and the significant findings of the study, along with an examination of these results. The data represents 101 articles (see Supplementary material), all focused on a specific OpEx approach used or investigated on the African continent. The descriptive analysis is presented here.

The funnel chart in Figure 3 provides a visual representation of the frequency of the ten OpEx approaches researched found in the literature sample. The chart arranges the approaches from top to bottom in descending order of frequency.

TQM was found to be the most prevalent approach used in the literature and appeared in 20.8% of articles, with an exceptionally high representation in South Africa, and most frequently applied in the manufacturing industry. Lean Six Sigma and BPR share the position of second-most prolific approaches; they were each found in 12.9% of the articles analyzed. Both approaches were most commonly found in South Africa, with Lean Six Sigma predominantly in the manufacturing industry and BPR in the financial industry. Combined, these three approaches account for 46.6% of the approaches found in the literature sampled. Tables 1 and 2 contain a breakdown of approaches per country and industry respectively.

It is interesting to note that Six Sigma is relatively scarce within the literature sample, whereas it is a technique popular in both Europe and the USA (Kirkham et al., 2014; Wasage, 2016). Four of the five Six Sigma articles focused on South Africa, where it was only the seventh most prevalent approach within the South African sample (Table 1).

Among the 101 articles that were analyzed, a total of 14 distinct industries were tallied as the focus areas of the implementations or investigations. These industries included the more traditional OpEx sphere of manufacturing, as well as nontraditional OpEx domains, namely, mining, education, construction, agriculture, finance, health care, software and IT, aviation, maritime, waste management, public administration and government, tourism and telecommunications.

Figure 4 visualizes the frequency with which these industries appeared in the sample. The category “Multiple” refers to articles that did not focus on a single industry, but rather into multiple industries. These articles were often applicable to small and medium-sized enterprises (SMEs) within a country.

OpEx approaches were found to be most prevalent within the manufacturing industry. Just over a third (35.6%) of the 101 articles analyzed focused on manufacturing. Figure 4 highlights the diversity that OpEx research seems to have achieved on the continent with 64.4% of the OpEx cases not in the manufacturing industry. The reader must remain conscious of the fact that this is a study of published literature, but due to the fact that the vast majority of articles in the samples were case studies, it does provide some insight into the preferences and proliferation of OpEx in practice.

It is also notable that education is the fourth most popular sector for OpEx implementation and study, perhaps due to its proximity to OpEx researchers’ place of work or study, and as such, the reader must be hesitant to conclude that OpEx is well-established away from higher education institutions. Two-thirds (66.7%) of these articles were indeed located within the higher education environment.

Apart from education, mining and construction industries also have notable levels of OpEx implementations represented in the sample of literature, along with some interesting domains such as tourism, maritime and waste management. The wider sample of 353 articles screened also contained some interesting implementation spheres, adding the real estate, hospitality, security and environmental domains to the already diverse list within the more focused sample. It is encouraging to see how many of the industries targeted align closely with areas targeted by the United Nation’s (UN) Sustainable Development Goals (SDGs) such as the education, maritime, public administration, waste management, agricultural and health-care domains. With the ability of OpEx approaches to minimize waste and create a value and customer-focused approach, better service delivery and a reduced environmental impact are just two of the many effects that OpEx could contribute toward the SDGs.

Section 4.2 described how certain OpEx approaches were found to be used or investigated across a diverse range of industries on the African continent. When the focus turned to an analysis by country, however, it was found that there was not as diverse a spread as that amongst industry types.

The five countries most prevalent in the literature sample, by number of articles detected per country, are: South Africa (55), Nigeria (16), Ghana (six), Zimbabwe (four) and Ethiopia (four). These five countries account for 84.2% of the articles in the sample. Table 1 shows a breakdown of the research sample by country and OpEx approach and grouped by region.

The infographic shown in Figure 5 provides a graphical representation of the distribution of the literature sample across the continent. Apart from providing a visualization of the proliferation of OpEx research across the continent, Figure 5 also deliberately echoes the format of Figure 2 to create a comparison between GDP and OpEx research. As can be seen by comparing the two maps, South Africa, Nigeria and Ghana are high performing on both GDP and OpEx research publications, whereas Egypt, Morocco and Algeria seem to be lagging behind in peer-reviewed research, published in English, when compared to their relative position on the GDP rankings. One of the limitations of this study is that the limited number of OpEx approaches investigated could explain some of this observation, but the ten OpEx approaches investigated do provide a relatively comprehensive sample of integrated OpEx approaches, and therefore, this limitation is actually unlikely to have an effect. A correlation between GDP and academic publications has, however, not been established, and therefore, this can only be an observation, but not a finding of this study. Furthermore, there could be a bias in the sample toward Anglophone countries, as also described by Van Leeuwen et al. (2001).

Figure 5 indicates that more than half (68.4%) of African countries were not represented in the data sample, which leaves only 31.6% of countries represented in the peer-reviewed sample, but a similar trend was noticed in the larger sample of 353 articles initially screened. This analysis prompted the Pareto analysis shown in Figure 6.

As can be seen from the Pareto analysis shown in Figure 6, only 14 (24.6%) of 57 countries in Africa were represented in the sample, with just over three-quarters (76.2%) of the articles being attributed to only three countries: South Africa, Nigeria and Ghana. This leaves the remaining 23.8% (24) of articles dispersed across 11 different countries. Thus, only 19.3% of African countries are represented in only 23.8% of the OpEx literature studied, with an average of only 1.8 articles, of the 101 in the data set, per country.

Again, however, the reader must keep in mind that only ten integrated OpEx approaches were selected to be studied. During the initial literature screening of the 1,100 articles, the researchers noted the smaller, individual OpEx techniques, which did identify some additional countries’ presence within the OpEx literature, but the sheer scope of doing a comprehensive search on both integrated OpEx approaches and their constituent techniques was not possible, given the constraints faced by the researchers.

Of the 353 “OpEx” + “Africa” articles initially screened for this study, only 101 were listed in either Scopus or WoS, which indicates that OpEx is, in fact, quite actively pursued on the continent, but that a relatively small amount of the work is published in high-quality journals. Of the 101 articles, more than half, 55, originated in South Africa. This mirrors the findings of North et al. (2020) in the geosciences sphere: that African research is underrepresented in the high-quality publications, with South Africa being responsible for a large sample within the continent. Figure 7 visualizes findings of a study by Kozma et al. (2018) on the research funding landscape in Africa and shows that South Africa is not just the most prolific country, but also seems to have access to the most research funding.

When comparing GDP ranking to the presence in the sample of 101 peer-reviewed articles, Egypt, Algeria and Morocco seem to underperform in terms of the OpEx research publications; however, the language bias, as discussed by Van Leeuwen et al. (2001), should be considered as a possible mediating factor. This does not, however, explain Egypt’s relative absence in the sample studied for this article. When considering Egypt’s high publication rate as shown in Figure 7(a), Egypt’s absence from the OpEx sample is even more conspicuous.

Zimbabwe seems to punch above its weight when comparing its OpEx research (fourth) ranking to its GDP (17th) ranking, as well as its population ranking (26th). Ghana’s OpEx research ranking (third) is also high as compared to its population ranking (14th) and GDP ranking (11th). Considering that these countries also seem to get relatively little research funding, it makes their OpEx research contributions notable.

The proliferation of OpEx publications across 14 different industries indicates a level of maturity in OpEx implementations where OpEx concepts have been translated for use in non-manufacturing settings. However, the high representation of case studies within the sample confirm the findings of Found et al. (2018) that OpEx research is practice-led.

As no other scoping reviews on OpEx in Africa were found in the sample of 1,100 initially screened, this paper represents a contribution to the existing OpEx body of knowledge from a regional, and specifically an African, perspective. The limitations, main findings and potential future opportunities presented by this review are discussed here.

Although the literature search covered 1,100 articles, screened 353 and reviewed 101, the researchers had to limit their scope due to time and resource constraints, meaning that the OpEx research in Africa as represented by this article and could benefit from further studies.

A second limitation arose from limiting the research scope to a select number of integrated OpEx approaches. This meant not conducting any analysis on where single OpEx techniques such as kanban, 5S or standardization were discussed.

Finally, the analysis of regional GDP and population density highlighted the fact that Northern Africa seems to be underrepresented in the analyzed sample of OpEx literature, which could allude to the possibility of a language bias in the study, as Northern African countries are mostly francophone, and only English publications were reviewed.

OpEx research is alive and well in Africa, although it is practice-led as OpEx research still is found to be in other regions as well (Found et al., 2018). The diversity of the industries that the research was done in seems to indicate a relative level of maturity in the roll-out of OpEx where the approaches are being customized for use in non-manufacturing fields.

However, upon deeper investigation, it becomes clear that the research landscape is dominated by a handful of countries, with South Africa contributing to more than half the publications studied. More than two-thirds of the African countries were not represented in neither the 101 sample nor the larger 353 sample. Ghana and Zimbabwe seem to contribute disproportionately well when compared to their populations and GDP rankings on the continent.

There was also a good proliferation of the ten OpEx approaches within the scope of this study with TQM being a clear winner in terms of most prevalent approach, and Six Sigma, ISO 9000/1 and TPM clearly getting less research focus than the other approaches, which were spread relatively evenly across the sample.

The purpose of insight into the use of and research in OpEx in Africa will assist in understanding the state of the continent’s development in OpEx research, and could enable the identification of research gaps, comparative studies, facilitate learning and implementation and identify opportunities for collaboration. Some practical and theoretical implications of this scoping review are:

• contributing to existing scoping review data on research in different fields in Africa for use in research funding and policy decision-making;

• providing a baseline for further such studies, which could explore the topic in more depth or from a different, comparative angle;

• providing a time-efficient overview source for OpEx researchers focusing on OpEx in Africa. This scoping review is especially useful in testing hypotheses on research in Africa, but also to identify research gaps in OpEx; and

• providing a database for researchers from inside and outside the continent looking for collaboration opportunities.

Although these findings are limited to published research, more than 80% of the articles were case studies, meaning that they might give an indication of the preferences and proliferation of OpEx in practice too. This review thus gave an overview of the current state of OpEx research on the continent but also enables learning for practitioners and researchers alike and highlighted several further research opportunities further to those mentioned in the article, which could easily align to the UN’s SDGs, such as:

1. The health care, agricultural, waste management and energy domains showed some, but relatively little, OpEx research activity and could benefit from a systematic literature review to create synergy among initiatives on the continent and investigate their alignment to the SDGs, as well as to identify research gaps.

2. Education was well-represented in the sample and could be ripe for more systematic reviews such as:

   • the school level targeted: higher, secondary, primary, or preschool;

   • the education process targeted: classroom or support; and

   • the extent of research alignment to the SDGs.

3. This scoping review could be supplemented by further scoping reviews as follows:

   • reviews with a similar scope but targeting a larger sample;

   • reviews focusing on francophone and Portuguese-speaking African countries; and

   • reviews that also look at the individual tools and techniques such as 5S, SMED Kanban, etc.

4. This scoping review could be followed up by systematic literature reviews focusing on a specific OpEx approach, OpEx in a specific African country or region or OpEx in a specific industry or the intersection of these domains.

The lack of research funding in many countries, as well as an unfavorable exchange rate to the US dollar, the currency of most academic journals, makes it more expensive and relatively harder for African researchers to compete on the international stage. This scoping review highlighted where OpEx is active and where it is lacking, highlighting opportunities where funding could be fruitful, most notably in Zimbabwe and Ghana, where researchers seem to have created research momentum in spite of funding challenges and might present a good return on investment to funders and collaborators.

Zooming out to the field of OpEx in general, the scoping review also highlighted the ambiguity that exists around the interpretation of various OpEx approaches, which constitutes an important and intimidating challenge to OpEx researchers. On the one hand, the proliferation of interpretations is a testimony to the rate at which these OpEx approaches gained traction in practice, but on the other hand, it is a risk to the credibility of the field. Within scientific thinking though, good theory is characterized by clear definitions (Wacker, 1998; Wacker, 2008), and therefore, if the field is to be taken seriously within the academic community, it would be good for significant research time to be invested and the ambitious task of converging understanding and distilling definitions and interpretations of the key terms in the field.

The fact that OpEx research tends to be practice-led is a testimony to its relevance in companies and organizations, and its proliferation among various domains, is, in turn, testimony to the universal principles that underpin it. It is thus a research field well worth promoting and refining, not only within the African context, but globally as well.

The supplementary material for this article can be found online.