In South Africa, supply chain management (SCM) in the public sector has emerged as one of the most topical issues among both management practitioners and researchers. This trend is largely attributable to the role of public SCM on the fulfilment of socio-economic imperatives by the government. It is widely acknowledged that public SCM is an important tool for the development of society through its contribution to both micro- and macroeconomic developments in the country (Dzuke & Naude 2015; Gurría 2016; Harland, Telgen & Callender 2013). Public SCM involves the spending of monetary resources by non-financial public enterprises such as state-owned enterprises, provincial and local governments (Ismail et al. 2014). For instance, it was projected that the South African government’s total expenditure would be at least R1.5 trillion between 2016 and 2019, across all spheres of government (South African National Treasury 2016). These funds would be directed to the procurement of goods, services and infrastructural improvements aimed at developing the country in different ways. The Department of Public Enterprises (2017) further reports that by the year 2020, the South African government would have invested in large-scale projects related to water, transport, electricity, telecommunications and infrastructure at an estimated cost of R3.2 trillion. Moreover, data provided by the World Bank showed that by the end of 2016, approximately 20.47% of the gross domestic product (GDP) in South Africa was attributed to public procurement spending (Global Economy 2017). Several authors (Ambe 2016; Khoza & Adam 2005; Mantaris 2014) add that the South African public sector has a significant impact on the economy, particularly the larger public companies that operate in key sectors of the economy, such as energy, telecommunications and transport. It is important, then, for public sector organisations in South Africa to continuously explore ways of improving the performance of their respective supply chains to ensure that their contributions to the national economy are maintained.

In spite of its fundamental contributions towards socio-economic development, public sector SCM in South Africa faces high levels of turbulence and uncertainty. As observed by some scholars (Dlomo 2016; Mafini & Pooe 2013; Munzhedzi 2016a) public organisations in South Africa operate in a highly unstable environment, which is both volatile and imperfect, which tends to limit their performance. According to Fourie (2015), unethical conduct involving fraud and corruption cost the South African government large amounts of money each year as fruitless and wasteful expenditure. For instance, in 2014, the South African government spent over R26.4 billion in ways that contravened laws and regulations, including corruption (Smart Procurement World 2014). Further exacerbating this situation is the lack of availability of a skilled SCM workforce, which remains one of the key constraints to the expansion of business operations in South Africa (Department of Higher Education and Training 2016; Heyns & Luke 2012). Policy also remains a major barrier to SCM in the South African public sector, particularly the fragmented and sometimes ambiguous legal status of the different legislative instruments for general and specific SCM practices (Sewpersadh & Mubangizi 2017; Smit 2015). This unclear legal framework creates uncertainty during the application of legal priority, regarding regulatory interpretation in cases of litigation involving SCM (South African National Treasury 2016). Other notable challenges facing public sector SCM include ineffective monitoring and evaluation, the lack of compliance with existing policies, poor planning and too much decentralisation of the procurement system (Ambe & Badenhorst-Weiss 2012a). As a result of these challenges, many South Africans do not trust the SCM processes in the public sector, and the general perception is that the public sector is failing to fulfil its mandate due to systemic problems in the entire public supply chain (O’Regan 2012; South African National Treasury 2016). Service delivery protests that have become commonplace in South Africa over the past few years demonstrate the feeling that people are not receiving the quantity or quality service that they need (Reddy 2016; Sartorius & Sartorius 2015). These issues provide a basis for further scientific inquiries to find relevant solutions.

Since public SCM has important socio-economic implications; it is essential to ensure that its processes are both efficient and effective (Ambe & Badenhorst-Weiss 2012b). It is necessary to develop an understanding of the risk factors that act as both constraints and barriers to the successful performance of public supply chains before applying solutions to improve both the efficiency and effectiveness of public sector SCM. As mentioned by Khoza and Adam (2005:16), getting the South African public sector to perform optimally depends on a host of factors. Such factors include but are not limited to the involvement of government (through government policies), the risk of supply, supply chain disruptions, lack of suitable or available suppliers, product performance, information security and internal business processes (Kelman n.d.; Tucker & Gilfilian 2013). An understanding of the effects of these individual risks on other SCM functions can be a tool for the mitigation of these risks, which leads to improved public sector supply chain performance (South African National Treasury 2015).

This article aims to test the relationships between supply chain risks, supply chain flexibility and supply chain performance in the South African public sector. The two specific objectives of the study are to determine the influence of supply chain risks on supply chain flexibility and to establish the influence of supply chain flexibility on supply chain performance. It is notable that despite the availability of extensive literature on supply chain risks, supply chain flexibility and supply chain performance (e.g. Ganga & Carpinetti 2011; Hoffman, Schiele & Krabbendam 2013; Sánchez & Pérez 2005; Stevenson & Spring 2007; Thome et al. 2014), the links between these factors remain largely untapped, especially in the African context. Additionally, previous studies focusing on SCM in the South African public sector (e.g. Ambe 2016; Ambe & Badenhorst-Weiss 2012b; Bolton 2006, 2016; Dlamini 2016; Mantaris 2014; Munzhedzi 2016b; Watermeyer 2011) overlooked these dimensional factors, as well as the possible links between them. This disregard for such a relationship is surprising, given the commitment of a lot of organisational resources to minimising the impact of supply chain risks. This study intends to address this existent research gap. It focuses on supply chain flexibility as a response to supply chain risks and assesses whether supply chain flexibility contributes to supply chain performance in the South African public sector. The study is important in that its results can be used by supply chain practitioners in the public sector to manage various risks experienced in the sector as a way of improving supply chain flexibility and performance.

The conceptual model presented in Figure 1 was developed for this study. The model identifies six supply chain risk dimensions that are the predictor variables (constructs). These are government policies, supply complexity, skills availability, supply performance monitoring, information security and process efficiency. The mediating variable is supply chain flexibility, which in turn connects to supply chain performance, which is the outcome variable. The relationships are connected using seven hypotheses (H1 to H7) that were tested in this study.

The first hypothesis of the study (H1) suggested that effective government policies lead to increased flexibility of the public supply chain. This hypothesis was supported in this study since government policies were statistically significant (β = 0.531; p = 0.008; t = 2.681) in predicting supply chain flexibility. This result implies that effective government policies act as a catalyst for supply chain flexibility in the public sector. An enabling policy framework (Hanks, Davies & Perera 2008; Turley & Perera 2014) usually supports public supply chains that can adapt and respond to changes with minimum costs regarding time, cost, quality and performance. Despite the availability of the various legislative frameworks, the public supply chain in South Africa remains inflexible and continues to face many challenges. Although public SCM in the country aims to promote principles of good governance and introduce a fair preferential procurement system (Ambe 2016), this has not been achieved. The public sector SCM system is highly decentralised, which is meant to allow managers within the different arms of government to control it. This has, however, made the SCM system highly fragmented, making it difficult for the government to obtain maximum value in the purchase and use of goods and services (South African National Treasury 2016).

The second hypothesis of the study (H2) suggested that increased supply complexity leads to decreased flexibility of the public supply chain. This hypothesis was supported because supply complexity was statistically significant (β = −0.137; p = 0.026; t = 2.232) in predicting supply chain flexibility. The negative beta result implies an inverse relationship between supply complexity and supply chain flexibility, such that the latter decreases as the former increases. Thus, it would be expected that a public supply chain exposed to a highly complex mix of supply would be unable to respond positively to any disruptive changes occurring in that supply chain.

The third hypothesis of the study (H3) suggested that availability of skills leads to increased flexibility of the public supply chain. This hypothesis was supported because skills availability was statistically significant (β = 0.820; p = 0.000; t = 3.455) in predicting supply chain flexibility. This result illustrates that the availability of qualified, knowledgeable and well-experienced human resources in the public sector improves the flexibility of that supply chain. A supply chain that is equipped with adequate and appropriate human resources can easily adapt and respond to any changes occurring within the market (Gómez-Cedeño et al. 2015). It also has to be noted that among the six supply chain risk factors considered in this study, skills availability scored the highest beta value. This demonstrates that the availability of skills is the most important and critical supply chain risk factor in determining the degree of flexibility within the South African public supply chain.

The fourth hypothesis (H4) proposed that the monitoring of supplier performance leads to increased flexibility of the public supply chain. This hypothesis was supported in this study because supplier performance monitoring was statistically significant (β = 0.236; p = 0.002; t = 3.100) in predicting supply chain flexibility. This result denotes that a public supply chain is likely to be highly flexible, provided the performance of suppliers to that supply chain is monitored. Lack of monitoring and evaluation across the entire South African public sector is a key area of deficiency (Nelson 2016). The deficiencies in monitoring and evaluation are linked to the absence of an effective control environment, and departments are placed in a difficult position to give effect to or implement monitoring and evaluation (Fourie 2011; Govender 2013). This has resulted in deviations or non-compliance that typically goes undetected or are identified after the fact (Nkuna & Nemutanzhela 2012).

The fifth hypothesis (H5) proposed that effective information security leads to increased flexibility of the public supply chain. This hypothesis was supported in this study because information security was statistically significant (β = 0.503; p = 0.041; t = 2.056) in predicting supply chain flexibility. This result validates that the more secure the information used in the public sector is, the more adaptable to changes the supply chain will be. Information security pertains to the prevention of unauthorised access, use, disclosure, disruption, modification, inspection, recording or destruction of information (Spagnoletti & Resca 2008). It is a general term that can be used regardless of the form the data may take. The chief area of concern for the field of information security is the balanced protection of the confidentiality, integrity and availability of data while maintaining a focus on efficient policy implementation without hindering organisation productivity. Given the high information technology illiteracy among many supply chain professionals in the South African public sector (Mkhize 2015; Sebake & Coetzee 2013), information security remains a major threat and could emanate from any of the available potential sources.

The sixth hypothesis (H6) suggested that process efficiency leads to increased flexibility of the public supply chain. This hypothesis was supported in this study because process efficiency was statistically significant (β = 0.473; p = 0.034; t = 2.313) in predicting supply chain flexibility. By implication, the adoption and implementation of efficient processes and procedures within the public sector lead to better supply chain flexibility. Process efficiency itself is the capability of human resources to conduct a certain process in the way that ensures minimised consumption of effort and energy (Malakooti 2013). Process inefficiency was identified by several authors (Ambe & Badenhorst-Weiss 2012a; Crous 2002; Fourie & Poggenpoel 2017) as a major factor affecting the implementation of SCM in the South African public sector. It thus remains that process efficiency still has to be addressed since it is a major risk facing public SCM in the country.

The seventh hypothesis suggested that supply chain flexibility leads to the increased performance of the public supply chain. This hypothesis was supported by this study because supply chain flexibility was statistically significant (β = 0.624; p = 0.026: t = 2.237) in predicting supply chain performance. This result suggests that the higher the flexibility of a public supply chain, the greater the performance of that supply chain. The result also shows that supply chain flexibility mediates the relationships between each supply chain risk and supply chain performance.

The first limitation of the study is that the respondents were based in Gauteng only. The second limitation is that the study did not consider all supply chain risks that exist in the public sector since this would have been beyond the scope of a single study. In addition, the use of the convenience sampling technique increased the susceptibility of the research sample to sampling bias.

Several suggestions for future research can be put forward. Firstly, since the study was inclusive of various public sector departments, future studies should consider specific government entities separately, such as state-owned enterprises, municipalities, government departments and constitutional entities. The scope of the study could be expanded to other supply chain risks excluded from this current study, such as among other things economic factors, social factors, political factors, environmental risk, human behaviour risk and legal risk. Since the current study was conducted using the quantitative methodology, a different view would be to conduct a similar study using a mixed method approach, which also involves the qualitative methodology where interviews are conducted. The results of the study could be more informative if the views of consultants working in the public sector were included and compared. This presents the need for conducting similar studies using perceptions of consultants working temporarily in the public sector’s supply chain departments. Since data were collected from supply chain professionals based in Gauteng, future samples could also include those provinces that were excluded from this study.

The results of this study provide statistical evidence that there is a relationship between supply chain risks, supply chain flexibility and supply chain performance in the South African public sector. While there is a lot of literature on supply chain risks, supply chain flexibility and supply chain performance, information on their relationship, specifically in the South African public sector, is rare. The study validates that supply chain risks, in this case government policies, supply complexity, availability of skills, supplier performance monitoring, information security and process efficiency exert significant influences on supply chain flexibility, which in turn influences supply chain performance in the public sector. The study further reports that supply chain flexibility can be improved through the management of the individual risks considered in this study, which, in turn, leads to superior supply chain performance.

The present study is important in several ways. Theoretically, the study is an addition to the available literature on supply chain risks, supply chain flexibility and supply chain performance. It is also an important source of information on research methodologies for future studies in SCM. Furthermore, the study provides a specific conceptualisation of the relationship between supply chain risks, supply chain flexibility and supply chain performance within the South African public sector, where no similar study had been conducted before.

Practically, the study provides information to supply chain professionals in the South African public sector regarding the improvement of supply chain performance. It underscores that the performance of public supply chain in South Africa can be improved by managing the six risk factors considered and their contribution to supply chain flexibility. This denotes that where supply chain underperformance is a challenge, such as when service delivery is inadequate, the solution is to minimise the effects of the risks mentioned in this study, which improves the flexibility of that supply chain. This, in turn, will lead to better supply chain performance. In this fashion, this study provides an important solution to the services delivery challenges facing the South African public sector. The solution is to mitigate the available supply chain risks, which fuels the flexibility of that supply chain, leading to better performance.