Traceability in multi-tier supply chains: insights from five case studies

Supply chain traceability has become a critical component in addressing growing consumer demands for transparency, regulatory requirements and sustainability objectives (Jia et al., 2025; Sodhi and Tang, 2019). Firms are increasingly expected to provide detailed insights into the origins of their products, the ethical sourcing of materials and the environmental impact of their supply chain activities. However, despite these expectations, implementing effective traceability mechanisms remains challenging, particularly in multi-tier supply chains characterised by complex networks of suppliers and intermediaries (Cui et al., 2024; Gualandris et al., 2021; Marttinen et al., 2024). The current approaches to traceability often fall short in addressing these complexities, leading to gaps in firms’ visibility, accountability and compliance.

In 2021, the European Union trade policy required firms to assess sustainability at multiple tiers in their supply chains instead of only accounting for the firm’s own operations and purchasing (European Commission, 2021), further strengthening stakeholders’ pressure. This trend continued with the European Parliament’s proposal for a product passport reporting on environmental impacts (European Parliament, 2023) and the Corporate Sustainability Reporting Directive (CSRD), which demands firms to report Scope 3 emissions from their supply chains (EUR-Lex, 2022). These examples clearly indicate that legislation and policies, along with traceability demands from end consumers, are growing.

Traceability can be defined as “the capability of a company for ascertaining provenance” (Sodhi and Tang, 2019, p. 2946) and as the level of a firm’s knowledge about the locations of their suppliers, from the original source to the end customer and the processes followed by their products (Cousins et al., 2019) – the definition we adopted for this study. To enhance traceability, firms must encompass multiple supply chain tiers by engaging with their suppliers more closely to ensure adherence to environmental and social standards, thus expanding the scope of supply chain sustainability (Bateman and Bonanni, 2019; Grimm et al., 2014). However, incorporating sustainability initiatives across these tiers remains difficult (Villena and Gioia, 2018), as weak or non-existent contracts with lower-tier suppliers hinder the implementation of such initiatives, causing firms to rely on first-tier suppliers for managing these tiers (Grimm et al., 2014). The challenge lies in identifying and engaging lower-tier suppliers, as they lack visibility in terms of their identity, operations and capabilities (Choi et al., 2001; Villena and Gioia, 2018; Wilhelm et al., 2016a). Focal firms may depend on first-tier suppliers for information on subsequent tiers; however, obtaining details about lower-tier suppliers remains particularly challenging (Hartmann and Moeller, 2014), especially when direct suppliers are unwilling to share information about their suppliers (Grimm et al., 2014; Wilhelm et al., 2016a). In addition, lower-tier suppliers may be located in emerging markets that are often geographically and institutionally distant from the focal firm (Awaysheh and Klassen, 2010), further obstructing the latter’s efforts to trace and engage with them. Thus, a firm’s ability to identify lower-tier suppliers and trace the origin of their raw materials can be considered critical for effective management of multi-tier supply chains.

In the context of multi-tier sustainable supply chain management (MT-SSCM), prior studies have investigated the factors critical for successful sub-supplier management (Grimm et al., 2014) and the contingency factors affecting firms’ approaches to managing lower-tier suppliers (Wilhelm et al., 2016b). Most studies have focused on the determinants of lower-tier supplier management, while traceability in multi-tier supply chains remains overlooked. When firms are unable to trace their supply chains, a crucial enabler for SSCM is missing (Garcia-Torres et al., 2019), leading to difficulties in managing lower-tier suppliers (Marttinen et al., 2024). Hence, understanding how traceability can be achieved by investigating its enabling factors is key to multi-tier management and sustainability. However, the understanding of the role of traceability in shaping firms’ management approaches in MT-SSCM remains limited, because recent studies on traceability have focused on product quality, consumer safety, risk management and technological solutions (Hoang et al., 2023; Razak et al., 2023; Zhou et al., 2024). Therefore, this study aims to investigate the following research question:

This study contributes to the intersection of traceability and multi-tier supply chain management (e.g. Tachizawa and Wong, 2014; Villena and Gioia, 2018; Wilhelm et al., 2016b) by examining how firms across industries and supply chain levels navigate traceability challenges (Grimm et al., 2014). Using a multiple case study approach on five multi-tier supply chains, the study showed that factors at the levels of organisation, relationship and multi-tier supply chain influence firms’ traceability efforts. The study identified the following factors as key factors: supply chain complexity, regulatory and industry environments, traceability resources and information sharing. The findings indicate that complex supply chains and resource constraints hinder traceability, often leading to firms’ relying on indirect or third-party management approaches in their multi-tier supply chains, even when facing stakeholder pressure. In addition, the study highlights the critical role of information sharing in facilitating traceability and enhancing tracking capabilities. Finally, the results show how these factors drive firms’ adoption of different multi-tier management approaches. Hence, this study contributes to the literature by demonstrating how traceability enables effective management of multi-tier supply chains.

Ensuring a sustainable supply is strongly linked to suppliers’ actions and performance. Sancha et al. (2016) state that a firm’s sustainability level cannot surpass that of its suppliers, and Villena and Gioia (2018, p. 83) continue that “a supply network cannot be sustainable if lower-tier suppliers are not addressing their social and environmental issues”. Thus, suppliers in the lower tiers need to embrace sustainability because the most significant environmental and social risks are associated with them (Kähkönen et al., 2023; Villena and Gioia, 2018). These suppliers, however, are the least regulated, monitored and equipped (Villena and Gioia, 2018), causing significant social failures in global supply chains (Wilhelm et al., 2016a).

In multi-tier supply chain management, the focus is not only on direct suppliers but also on lower-tier suppliers. Managing more suppliers than first-tier suppliers is difficult for managers because of the newness and complexity of issues regarding environmental and social sustainability (Grimm et al., 2016). In addition, effectively influencing firms’ practices beyond the direct buyer–supplier relationship is challenging (Seuring et al., 2008). A firm’s regional and contractual distance from lower-tier suppliers increases information asymmetry between the focal firm, first-tier and lower-tier suppliers (Sarkis et al., 2011).

Such difficulties may either make focal firms passive towards managing multiple tiers of suppliers (Wilhelm et al., 2016a) or increase their reliance on their first-tier suppliers to manage sub-suppliers (Grimm et al., 2014). Lee and Klassen (2008) state that, although direct pressure on lower-tier suppliers is not common, motivating first-tier suppliers to acknowledge sustainability-related factors in their supply chain management helps focal firms indirectly manage their lower tiers. Tachizawa and Wong (2014) found that firms can take four different management approaches for managing sustainability in multi-tier supply chains: direct, indirect, work with third parties and don’t bother. A direct approach indicates that the focal firm manages its lower-tier suppliers directly, whereas the indirect approach indicates that a first-tier supplier oversees lower-tier suppliers’ sustainability practices. Collaborating with external entities, such as non-governmental organisations (NGOs), to enhance sustainability is called working with third parties. Finally, don’t bother approach refers to situations in which a firm does not engage in managing its lower-tier suppliers. Tachizawa and Wong (2014) found that a firm’s choice of management approach for multi-tier supply chains is affected by various contingent factors, namely, the distance between the supply chain members, material criticality, power, dependence and knowledge resources. Grimm et al. (2014) identified 14 factors that play critical roles in lower-tier (sub-supplier) management, including, for example, trust, long-term commitment, willingness to provide sub-supplier information and geographical and cultural distance. Wilhelm et al. (2016b) identified several factors, including complexity and transparency of supply chains, the type of sustainability in question, power imbalances and the technical expertise of suppliers, that determine how and when firms extend their sustainability strategies to their sub-suppliers. These studies do not focus, however, on traceability and how traceability could be better achieved in multi-tier supply chains. This might be partly because traceability requirements have grown during recent years, whereas earlier the focus was more on overall sustainability.

Firms that take a multi-tier perspective in managing their supply chains are better able to manage, for example, sustainability and risks related to lower tiers (Grimm et al., 2016; Kähkönen et al., 2023; Zehendner et al., 2021). However, Grimm et al. (2014) and Wilhelm et al. (2016b) found that multi-tier supply chain management with lower tiers is not always possible. Firms must be able to identify their lower-tier suppliers and trace the origin of their raw materials. Hence, firms must be able to gather information about their lower-tier suppliers and develop strategies to achieve traceability.

The research on supply chain traceability first started in the late 1990s, which was related to food safety in the food industry (e.g. Viaene and Verbeke, 1998; Wilson and Clarke, 1998). However, with the growing requirements for sustainability, the role of supply chain traceability and related research has also changed. In particular, the exploration of traceability in relation to sustainability is a recent development in the research related to supply chain management (Hastig and Sodhi, 2020; Sodhi and Tang, 2019). Contributors include Garcia-Torres et al. (2019), who examine the overlap of sustainability and traceability and study how companies execute traceability for sustainability within their global supply chains and their role in fostering SSCM. Garcia-Torres et al. (2019, p. 98) suggest that traceability for sustainability “can help minimise sustainability risks and impacts by the mimetic effect of inter-organisational collaboration strategies, alliances and initiatives, distributing and transferring knowledge, learning and resources more evenly along the entire SC”. Kumar et al. (2017) studied how traceability contributes to sustainability and identified traceability as a vital component in pursuing sustainability. They found that traceability integrates information and can be seen as a competitive factor because it enables providing detailed information to consumers. However, the studies by Garcia-Torres et al. (2019) and Kumar et al. (2017) lacked empirical research as the studies are conceptual ones. Furthermore, many recent contributions, such as those by Hastig and Sodhi (2020), Agrawal et al. (2021) and Zhou et al. (2024), focused on exploring the opportunities of implementing traceability in supply chains through technological solutions. The study by Hastig and Sodhi (2020) is a conceptual and Zhou et al. (2024) focused on the focal firms, thus ignoring lower-tier suppliers. Agrawal et al. (2021) used a simulation-based demonstration and claimed to use a multi-tier perspective; however, the perspective was more from the perspective of a traditional supply chain. Some studies have also investigated the drivers that enable the adoption of blockchain to achieve sustainable food security (Yadav et al., 2021) and the drivers and barriers to Industry 4.0 adoption for extending sustainability within the context of multi-tier manufacturing supply chain (Sharma et al., 2021). Despite the growing research on traceability, a lack of empirical research and many unanswered questions remain, for instance, regarding the role of traceability in strategic decision-making (Hoang et al., 2023).

According to Garcia-Torres et al. (2022), traceability and transparency can be regarded as key instruments for fostering cooperation and ensuring coordination to achieve sustainability within supply chains. Fernie et al. (2010) discovered that the degree of transparency between organisations and their willingness to share information significantly promotes enhancement in firms’ tracking and tracing capabilities within supply chains, highlighting the value of mutual openness and information sharing in enhancing traceability. Garcia-Torres et al. (2019) found that transparency can be considered a driver of traceability, as both concepts are often linked. According to Schäfer (2023), traceability, visibility and disclosure are variably linked to transparency, ranging from being synonymous to independent or even integral components or pre-requisites of transparency. When traceability can be defined as a firm’s capability to ensure the origin by identifying suppliers and knowing their location and processes (Cousins et al., 2019; Sodhi and Tang, 2019), transparency can be understood as a firm’s openness to revealing information about its upstream operations and products to the public (Sodhi and Tang, 2019) or information sharing among organisations (Garcia-Torres et al., 2022) to enable traceability by reporting to and communicating with key stakeholders (Morgan et al., 2018). This study adopts the latter perspective, positing that transparency is essential for achieving traceability.

Kumar et al. (2017) state that multiple brands have identified traceability as a competitive factor, but recent developments emphasise traceability as a must-have supply chain element. Existing research mainly studies traceability in the context of direct supplier management, but traceability is about identifying also the lower-tier suppliers and tracing the supply chain (Cousins et al., 2019; Sodhi and Tang, 2019), which tightly connects it to a multi-tier perspective. If firms cannot trace their supply chains, managing lower-tier suppliers becomes difficult. Research on the topic is, however, missing. Existing research lacks contributions on traceability from the multi-tier perspective and especially on the connection between traceability and the management approaches of lower-tier suppliers. Thus, discovering key factors that affect traceability in multi-tier supply chains can improve lower-tier supplier management and an understanding of the management approaches that can be taken in MT-SSCM.

To investigate the emerging subject of traceability for sustainability, this study has adopted an exploratory, inductive approach. The research method chosen is a multiple-case study design, featuring several embedded units of analysis (Eisenhardt, 1989; Yin, 2009). This methodology allows for the exploration of a broad spectrum of perspectives, enriching the overall comprehension of the topic. The study examines five multi-tier supply chains that involve five focal firms, 10 first-tier suppliers and 10 lower-tier suppliers comprising various industries. Using a multiple case study approach allows for an investigation from different contexts and viewpoints, which can increase the credibility and generalisability of the findings (Yin, 2009).

This research focused on focal firms in Finland and their European suppliers based in Finland, Germany, Belgium and Italy. Since 2021, Finland has been ranked first in the annual global ranking of sustainable development and was among the top 3 many years before that (Sachs et al., 2021); thus, Finland offers an excellent context for studying sustainability-related issues. The official ranking of the Sustainable Brand Index (SBI) in 2018 guided the selection of focal firms. The SBI is an annual independent study that evaluates more than 1000 brands in the Nordics and The Netherlands (Sustainable Brand Index, 2018). The focal firms were selected from the top-ranked 100 Finnish firms, presuming them as sustainability leaders within the Finnish market and thus committed to practicing sustainable supply management and possessing advanced knowledge of the field, as suggested in previous studies (e.g. Pagell and Wu, 2009; Villena and Gioia, 2018). Firms representing different industries were included in the study as called for by Senyo and Osabutey (2023) to increase the empirical research perspectives on sustainability in multi-tier supply chains. Firms’ sustainability reports and websites were screened to ensure that they prioritised sustainability in their purchasing and supply management. The first- and lower-tier suppliers were selected through snowball sampling; during the interviews, the focal firms were asked to nominate 1–3 suppliers who held strategic significance for their operations or those with whom they faced challenges in terms of achieving sustainability.

In total, 44 informants participated in semi-structured interviews that lasted from 60 to 90 min. The interviews were primarily conducted face-to-face; however, due to the geographical spread of suppliers, some were conducted virtually. Figure 1 presents the case supply chains and provides firm- and interview-related information. The informants were selected based on their expertise in purchasing, supply chain management and sustainability, and they were, for example, sourcing and supply chain managers, purchasing directors, corporate social responsibility managers and sustainability coordinators. Account managers were interviewed to fill the gap between the buyer company and the supplier firm’s purchasing department.

To ensure a comprehensive understanding and validate the collected data, approximately two representatives from each firm were interviewed using a triangulation approach (Eisenhardt and Graebner, 2007). However, in some cases, only one informant was interviewed because of the extensive knowledge of the interviewee and the small company size. The informants were asked questions related to, for instance, the ability to trace products, services and raw materials, their knowledge about the members in their supply chains, the factors that help them in ensuring lower-tier suppliers’ sustainability and the challenges they have faced. The study was conducted by following the guidelines of Eisenhardt (1989) and Strauss and Corbin (1998) in terms of the saturation point, indicating sufficiency of interviews as a situation in which new information produces little or no change to the codebook. To guarantee reliability and validity, a number of precautionary measures (Eisenhardt and Graebner, 2007), such as the use of multiple sources of evidence, investigator triangulation, establishment of the chain of evidence and creating a case study protocol and database, were used.

The data from the five multi-tier supply chains were analysed using NVivo qualitative data analysis software and a systematic inductive approach to concept development, as proposed by Gioia et al. (2013). Special attention was paid to capturing informants’ perspectives that uncovered new concepts beyond revisiting established ones. The research methodology included a first-order analysis using informant-centric terms and codes and a second-order analysis employing researcher-centric concepts, themes and dimensions to discover the enablers and barriers of traceability for sustainability.  Appendix 1 illustrates the transition of raw data to identified emergent factors in detail. Creating such a data structure is a critical aspect of demonstrating rigour in qualitative research (Gioia et al., 2013; Pratt, 2008).

The objective was to uncover key factors influencing a firm’s ability to trace the origins of its supplies, thereby gaining insights into the enablers and obstacles impacting traceability and MT-SSCM approaches. First, an in-depth analysis of data at the firm level was conducted, and the identified firm-level factors resulted in four main dimensions. Then, a broader supply chain-level analysis was conducted to detect patterns prevalent across different supply chains, allowing for a comparative understanding of these patterns among various industries.

As a result of firm and supply chain-level analysis, four factors affecting traceability were identified: supply chain complexity; regulatory and industry environments; traceability resources; and information sharing.Table 1 displays the factors that may either support or hinder traceability in each firm.  Appendix 2 provides detailed information about the case firms’ traceability and MT-SSCM efforts. The following sub-sections elaborate on the insights from each of these factors.

Supply chain complexity was identified as a significant contributing factor to traceability, comprising the following aspects: number of intermediaries, geographical distance and dispersion, number of suppliers and product or service complexity. The firms emphasised the effect that the number of intermediaries involved in a supply chain has on the complexity of tracing the origins of products and services. Each layer of intermediaries with its own set of suppliers was observed to increase the number of entities that needed to be traced, contributing to the potential for information distortion or loss. Because of their long and complex supply chains, some firms found it difficult and, in some cases, impossible to trace back the origins of their products and raw materials:

In particular, buying from importers was emphasised when it came to complicating firms’ traceability efforts:

The biggest traceability challenges were related to global supply chains. An informant from FT Textile Products mentioned that working with geographically distant suppliers is challenging because of the complex supply chains consisting of many globally dispersed suppliers and outsourced operations. In contrast, geographically close suppliers were easier to trace:

To simplify the supply chain structure, firms reported pursuing direct contracts with manufacturers, which can bring both traceability and cost-related benefits:

The firms reported the benefits of vertical integration of the production process; firms found tracing easier if their direct supplier was responsible for many steps in the production process. For example, the lengths of the supply chains of FF Textile Retail varied, depending on how much of the manufacturing process was handled by their supplier; although their partner from Turkey oversaw most of the production process, their Latvian supplier may only be responsible for printing fabrics. The focal firm found it beneficial for traceability that its supplier, FT Textile Products, managed most of the process:

Vertical integration and supply chain non-complexity were also found to help auditing and lower-tier supplier management because it could increase the coverage of the audited supply chain members:

Furthermore, the number of suppliers was found to contribute to the level of supply chain complexity. For instance, a large number of suppliers made it difficult to follow and maintain information about their supply chains:

Based on the data, we identified product and service complexity as an aspect influencing the degree of supply chain complexity, thus contributing to the ability to trace the origin. The informants stressed that the less processed the product or raw material was, the easier it is to recognise the suppliers:

Firms with less complex supply chains were able to trace, acquire information about and visit lower-tier suppliers more easily, supporting a more direct approach to lower-tier supplier management:

In contrast, firms with more complex supply chains, such as LT Confiture, faced traceability-related challenges that affected their approach towards multi-tier supply chain management:

Regulatory and industry environments, including regulatory pressure for traceability, industry-wide traceability mechanisms and traceability requirements from customers, were identified as having a significant impact on achieving traceability. The impact of regulatory pressure on traceability was particularly stressed by firms in the food industry; the ability to trace suppliers often depends on its product category, as different product groups have different requirements in terms of the extent of required information. Legislation was highlighted as a key enabler of traceability:

Traceability is often realised through traceability testing. For instance, for LT Packaging, a supplier of FT Meat, traceability is a number one priority. They stated that traceability tests must be conducted for direct food contact products:

Products or raw materials that received no regulatory pressure for traceability were more difficult to trace:

Importantly, regulatory requirements for traceability create a common ground in that firms do not have to trade off. According to LT Grain Mill 2, legislation for traceability has provided a solid foundation for environmental and social sustainability in terms of purchasing and supply management. They also stated that, beyond legislation, additional industry requirements for sustainability and traceability create a common ground, allowing them to compete on an equal footing with their competitors in terms of pricing. Regulatory and industry environments can also have an impact on supply chain configuration:

The results indicated that industry-wide traceability mechanisms, such as product passports, third-party certifications and blockchain technology, can enable firms to achieve traceability. Such mechanisms were reported to increase the levels of reliability in terms of tracing products across supply chains, accessing origin information and possessing the potential to provide information to stakeholders and consumers. Members of the textile retail supply chain, including FF Textile Retail, described how industry-specific certifications helped them trace the country of origin for cotton.

You can surely trace the production of yarn, regardless of the partner. They always have that information available. However, managing the information is up to the yarn manufacturer. If the manufacturer is certified, information will be obtained. Otherwise, they may say, “well, usually it is from these countries,” and then they mix the cotton from different countries, because they do not keep them separately. Therefore, you can never be absolutely sure. (FF Textile Retail).

Thus, lower-tier suppliers’ use of certifications was seen as enabling traceability for the focal firm. In addition, enforcing certain certification requirements on suppliers was found to trigger a beneficial chain reaction, enhancing traceability and sustainability within multi-tier supply chains. The representatives from both FT Bakery and FT Beverage Manufacturing expressed parallel views regarding the implications of enforcing certification requirements on suppliers. Suppliers reacting to these requirements were observed to either adopt certifications or construct their own systems for overseeing their upstream partners, thereby increasing traceability. LT Grain Mill 1 provided an example of how product passports for traceability are used in the food industry:

Related to industry-wide traceability mechanisms, several firms were interested in blockchain technology because it can provide easy access to information across supply chain tiers. However, there were concerns about the practicalities. The informant from LT Confiture highlighted the challenges faced in hazelnut supply chains in which upstream actors could not be properly traced and identified owing to the complex nature of the industry, comprising vast networks of crackers and farms. Although LT Confiture was interested in blockchain technology, it lacked practical knowledge about how tracing the origin in such supply chains would actually work, especially considering the potential lack of suppliers’ necessary capabilities:

Thus, suppliers would also need to possess the capabilities to effectively support traceability and transparency initiatives. To address these challenges, the informant from LT Confiture emphasised the importance of making investments in traceability that are mutually beneficial for suppliers; they highlighted the need to engage and motivate suppliers, ensuring that they comprehend the advantages associated with investing in traceability initiatives.

The participants highlighted the significance of increasing customer demand for traceability. Traceability efforts are linked to the pressures firms receive from customers and consumers and the visibility of products to customers. This demand, coupled with the growing consumer consciousness, can accelerate firms’ efforts to implement mechanisms for traceability. However, firms acknowledged the unfortunate reality that having full traceability in today’s complex supply chains is not always achievable:

Inter-organisational information sharing is a critical aspect of traceability. Key elements that were found to contribute to this were the supplier’s willingness to disclose information to their buyers, the supplier’s capability to collect and share information and power dynamics. Regarding the supplier’s willingness to disclose information, contrasting results were noted across different firms. Some firms found that their suppliers shared essential information quite willingly, while others reported challenges in acquiring the required information from their suppliers. Firms such as LT Bakery Products and FF Accommodation reported that their suppliers were sometimes unwilling to disclose information about their suppliers or sources:

Conversely, interviewees from FF Textile Retail and FF Food Service observed a recent shift in that suppliers are now more willing to share information. Compared to a decade ago, when many suppliers guarded their raw material sources as trade secrets, this recent change significantly facilitates traceability:

They continued that they publicly disclosed the origins of their raw materials because they perceived no need for secrecy in doing so from their standpoint.

Furthermore, the data revealed instances in which suppliers failed to notify the buying firm about changes in lower-tier suppliers and countries, despite the contractual requirement to do so. In response to the information disclosure issue, a lower-tier supplier from the accommodation supply chain reported that they did not want to share detailed information with their customers sometimes:

They also added that regardless of any changes in the supplier base or non-disclosure of information related to the supplier or origin of raw materials, they would ensure that sustainability issues remain under their control. This example demonstrates that full traceability to the downstream supply chain requires an uninterrupted information flow through all supply chain members.

Hence, the supplier’s capability to collect and share information emerged as an important element for enabling traceability across multi-tier supply chains. For instance, the traceability capabilities of the lower-tier supplier LT Grain enabled FT Beverage Manufacturer to trace its supply chains:

When suppliers are equipped with the necessary tools and knowledge to collect relevant information, they can effectively share it with other stakeholders within the supply chain. This underscores the importance of motivating suppliers to improve their traceability capabilities, as they may lack such capabilities:

In terms of accessing supply chain information, the firms mentioned how power dynamics among supply chain partners may affect information sharing. For example, a powerful firm can easily gather information from suppliers:

It was also mentioned that this led to enhanced traceability and the capability to engage in discussions with lower-tier suppliers. In contrast, the data showed that it can be difficult to acquire information from suppliers if a supplier has more power than the buyer:

Based on the data, accessing even general information about lower-tier suppliers, often limited to the country of origin or the supplier’s name, was challenging and had implications for firms’ MT-SSCM. For instance, insufficient information sharing caused firms’ failures in managing their lower-tier suppliers directly:

In addition, possessing minimal information about lower-tier suppliers can force companies into a position in which they must rely solely on their suppliers’ assurances:

Firm’s resources for traceability work, comprising information systems and tools and staff allocation, were identified as an important element to achieve traceability. Information systems and tools were recognised as critical for tracing and storing information. The development and application of such systems seemed to vary across different industries, with the food industry having the lead:

Some companies, such as LT Beverages and LT Chemical Products, emphasised the need for better information systems and tools for tracking and tracing goods and services effectively, because their existing traceability systems were insufficient in catering to the complexities of their supply chains and supporting MT-SSCM.

Traceability systems and tools were considered to form the key for collecting information across supply chain tiers and facilitating MT-SSCM; however, some challenges were observed in terms of their practical implementation. Firms observed that significant amounts of time and resources were required to maintain and update systems. Furthermore, the potential for inaccuracies arising because suppliers frequently changed their raw material sources could not be ignored. However, implementing traceability systems can undeniably enhance sustainability by increasing transparency and improving supplier management. Importantly, a lack of information systems and traceability tools in a firm was found to be linked to its passiveness towards MT-SSCM. Highlighting industry-related differences, an informant from LT Chemical Products explained the reasons for not prioritising lower-tier supplier management:

The informants emphasised the significance of human resources’ allocation in the staff to effectively support and facilitate traceability for sustainability. These resources enabled tracing and monitoring of suppliers and products throughout the supply chain. In particular, the lack of staff for tracing and ensuring sustainability was noted in their global supply chains, as highlighted in the case of FT Agri-food Production, whose strategy was to focus on relationship management and indirect management through direct suppliers:

The aim of this paper was to examine how traceability can be achieved in multi-tier supply chains by identifying enabling factors and their effects on firms’ MT-SSCM. The results indicate that the case firms faced many challenges while they increasingly sought to enhance traceability in their multi-tier supply chains, further affecting their approaches and motivation towards MT-SSCM. Tachizawa and Wong (2014) categorised MT-SSCM approaches into the following four types: direct, indirect, work with third parties and don’t bother. Based on the findings, we propose the following four key factors for traceability that affect these MT-SSCM approaches: supply chain complexity, regulatory and industry environments, information sharing and traceability resources. We further propose that these factors represent factors at three different levels: the multi-tier supply chain level, the relationship level and the organisational level. Supply chain complexity and the regulatory and industry environments are observable at the multi-tier supply chain level, while information sharing is a relationship-level factor and traceability resources are at the organisational level. Figure 2 shows the framework for traceability and MT-SSCM and illustrates how the identified key factors affect management approaches in multi-tier supply chains.

The case studies show that similar to the findings of Sodhi and Tang (2019), regulations act as catalysts for achieving traceability. Supportive regulatory and industry frameworks provide firms with a common ground for their operations, mandating sustainability and traceability standards that ensure transparency and accountability. Hence, regulatory and industry environments can enforce information sharing and the adoption of information systems and traceability technologies, enabling more effective MT-SSCM. This study highlights the value of industry-wide traceability mechanisms, such as sustainability certifications, that cover the entire multi-tier supply chains and enhance traceability by providing insights into the upstream supply chain. For example, in the food industry, where traceability usually plays an important role (Razak et al., 2024) and where regulatory requirements demand it, traceability systems that enable effective tracing were widely adopted. The results also show that food industry companies are managing lower-tier suppliers directly more often than companies operating in other industries.

We also found that the complexity of a firm’s supply chain (in terms of the number of intermediaries, geographical distance and dispersion, number of suppliers and product or service complexity) is a multi-tier supply chain level factor that can influence the management approach that firms take towards the lower-tier suppliers. Firms with more complex, multi-layered supply chains are inclined towards an indirect approach in that they do not prioritise interactions with lower-tier suppliers (see Figure 2). Conversely, firms with less complex or more linear supply chains seem more inclined to establish direct contact with their lower-tier suppliers because, as Gualandris et al. (2021) mentioned, a simpler structure facilitates easier identification and closer relationships. The complex configuration of supply chains, where different levels of disclosure of product origin to different participants are impractical in terms of traceability, makes it challenging to have varying levels of disclosure to different supply chain participants. The results indicate that amid significant regulatory pressures and a relatively simple supply chain structure, firms are more inclined to directly manage their lower-tier suppliers to ensure compliance and traceability. Hence, we propose the following:

At the relationship level, it was found that suppliers’ reluctance to share information causes information asymmetry and undermines buyers’ MT-SSCM efforts. The cases show that if suppliers are not willing or able to share information on their lower-tier suppliers, the buyers face difficulties in getting information about the lower tiers. This emphasises the importance of collaborative efforts and open communication across organisations to enable traceability and thus ensure effective MT-SSCM. Trust building fosters information sharing and traceability, while information gaps caused by uncertainty, especially in complex supply chains, can erode trust. Kumar et al. (2017) suggested that by enabling the communication of product-related information, traceability can foster trust building across firms. Furthermore, this study indicated the influence of power dynamics on information sharing. Previous studies have suggested that a power imbalance can influence achieving of sustainability objectives (Corsi and Filippini, 2023; Touboulic et al., 2014). We demonstrate that firms in a stronger power position are better positioned to access supply chain information, enabling traceability and direct lower-tier supplier management. Conversely, a weaker power position may restrict information sharing and compel firms to adopt an indirect MT-SSCM approach, limiting the management of lower-tier suppliers. In situations of constrained information sharing – due to a lack of trust, resources or effective strategic possibilities – firms may resort to managing lower-tier suppliers through an indirect approach or by engaging third parties, reflecting a strategic adjustment to cope with barriers to information flow, even under direct management intent:

The case studies reveal that when firms lack sufficient resources to implement practices that enable traceability mechanisms, even substantial pressures from stakeholders – such as regulatory bodies or customers – fail to inspire meaningful actions. In such situations, organisational resource constraints overshadow external demands, leading firms to deprioritise traceability initiatives. This was particularly emphasised by firms with extensive supplier bases and diverse product categories, while those with more manageable supply bases found it easier to control, suggesting that the perceived costs and complexities associated with establishing robust traceability mechanisms outweigh the potential risks of non-compliance or reputational damage. Consequently, despite stakeholders’ expectations, firms may either resort to superficial compliance or avoid complying altogether, depending on challenges such as insufficient staff, information systems and adequate traceability tools (Kim and Davis, 2016; Villena and Gioia, 2018; Wilhelm et al., 2016a). The results show that the lack of traceability resources, such as information systems and tools, was linked to the passiveness towards MT-SSCM and the pursuit of traceability. Highly developed tools and information systems, however, would support better lower-tier management, but the case companies were lacking these kinds of resources. Thus, the role of organisational resources in facilitating traceability is significant and highly affects the approach that the firms can take towards lower-tier management:

This study contributes to the research on MT-SSCM (Tachizawa and Wong, 2014; Villena and Gioia, 2018; Wilhelm et al., 2016b) and traceability for sustainability (Garcia-Torres et al., 2019; Garcia-Torres et al., 2022) by focusing on the intersection of these. We contribute by showing that supply chain complexity, regulatory and industry environments, information sharing and traceability resources are the key factors for traceability in multi-tier supply chains and that these factors appear at three different levels: the multi-tier supply chain, the relationship and the organisational level. Traceability resources are organisational-level factors, and each company has its own resources for ensuring traceability. Information sharing occurs at the relationship level because it takes place within dyadic buyer–supplier relationships between two parties. Supply chain complexity and the regulatory and industry environments are factors that are present at the multi-tier supply chain and industry level.

The findings emphasise the role of multi-tier level factors of regulatory requirements and industry environments in driving traceability initiatives. Previous studies (e.g. Garcia-Torres et al., 2022) have acknowledged the contrast between a lack of regulation as a barrier to traceability and the existence of regulation as a source of pressure to disclose information (Sodhi and Tang, 2019). However, this study indicates that in the absence of sufficient resources for traceability, even stakeholder pressure can be ineffective. The results further show that a non-complex supply chain configuration supports firms in their traceability efforts. The results highlight that transparency fades across multiple tiers, aligning with the study by Roth et al. (2008) and revealing uncertainties related to MT-SSCM, particularly in long and complex supply chains in which firms may lack control. Gualandris et al. (2021) stated that supply chain structures support or hinder collective outcomes, such as transparency. Seuring et al. (2008) found that the global scope of supply relationships increases firms’ challenges in influencing practices beyond the direct buyer–supplier relationship. In particular, tracing and reaching lower-tier suppliers located in geographically and institutionally distant countries remains difficult for firms, as suggested by Awaysheh and Klassen (2010). Consistent with prior research (Sarkis et al., 2011; Simpson et al., 2007), a firm’s geographical and contractual distance from lower-tier suppliers seems to amplify information asymmetry and cause a lack of information. This distance can create barriers to communication, limiting a comprehensive overview of suppliers’ operations and practices and thus posing challenges to managing sustainability within a multi-tier supply chain.

Moreover, our research aligns with that of Fernie et al. (2010) and highlights that enhanced inter-organisational transparency and a willingness to share information facilitate the development of firms’ tracking and tracing capabilities within supply chains. The findings reveal that uncertainty in MT-SSCM is because of firms’ limited information and control. Firms are often unaware of the details about their supply chain and lower-tier suppliers because of the complexity of supply chains, insufficient regulatory pressure and a lack of information sharing and traceability resources, underscoring the importance of direct suppliers’ actions and emphasising that firms must prioritise collaboration with their direct suppliers. This study demonstrates that a firm’s ability to trace the origin of raw materials, products and services can influence its motivation and approach towards MT-SSCM. Thus, we further contribute by showing that firms’ approaches to managing multi-tier supply chains depend on different factors at the multi-tier supply chain, relationship and organisational level. Therefore, the research contributes to both the MT-SSCM and the research on managing multi-tier supply chains (e.g. Mena et al., 2013).

Previous research has recognised traceability as a key mechanism for coordination and collaboration in (sustainable) supply chains, highlighting its significant enabling role in SSCM (Garcia-Torres et al., 2019; Garcia-Torres et al., 2022). This study contributes to the literature on traceability (Garcia-Torres et al., 2019; Garcia-Torres et al., 2022) and MT-SSCM (Tachizawa and Wong, 2014; Villena and Gioia, 2018; Wilhelm et al., 2016b) through its findings that extend the previous view by highlighting the significant role of traceability as a facilitator of MT-SSCM and showing that if firms are unable to trace their supply chains, managing lower-tier suppliers becomes an unattainable task. This study drew from previous research on the factors affecting MT-SSCM (Grimm et al., 2014; Tachizawa and Wong, 2014; Wilhelm et al., 2016b) by underlining the role of traceability in driving and enhancing MT-SSCM.

This study offers valuable insights for purchasing and supply chain professionals, highlighting strategies to enhance traceability, manage lower-tier suppliers and improve supplier relationships. Managers should recognise the factors that can enhance or limit a firm’s ability to achieve traceability in multi-tier supply chains. These factors can appear at the levels of organisation, relationship and multi-tier supply chain and thus, it is critical that managers take a multi-tier perspective when defining strategies, for example, to ensure traceability. A firm’s access to comprehensive information about its supply chains and supplier practices enables it to achieve sustainability across multiple supply chain tiers. This may require firms’ efforts towards supply chain reconfiguration by focusing on selecting trustworthy suppliers with good traceability and sustainability capabilities and pursuing collaboration with suppliers committed to transparency and traceability. Firms should be mindful of the complexities within their supply chains that can impede MT-SSCM efforts.

The framework presented in Figure 2 offers a blueprint that managers can use when defining strategies for managing lower-tier suppliers. For example, it shows that a direct approach should be taken when industry-specific regulations and requirements are stringent. Those with less complex supply chains have a greater opportunity to manage and engage with lower-tier suppliers directly to enhance sustainability. Conversely, when the supply chain complexity is high, investing in collaboration and engagement with direct suppliers to manage lower-tier suppliers remains crucial. By fostering close relationships with suppliers, firms can encourage them to be more transparent about their practices and provide the necessary information to ensure traceability. By building strong relationships, firms can create a culture of transparency that is essential for traceability and MT-SSCM. Finally, the results emphasise that every firm in the supply chain plays a critical role in achieving traceability, thus requiring a multi-tier perspective. Traceability and transparency are needed for creating a truly sustainable supply chain and to respond to the tightening legislation, policies and demands.

This study contributes to the MT-SSCM literature by identifying factors influencing traceability for sustainability in the context of multi-tier supply chains and developing a deeper understanding of how traceability facilitates MT-SSCM through tracing the origins of raw material suppliers. By providing empirical evidence from 25 companies within three supply chain tiers and five supply chains, this study has answered the call for more research on multi-tier supply chain design in light of the presence of lower-tier suppliers.

However, it is vital to recognise the study’s limitations that may impact the interpretation of the findings. The scope of the study is limited to the European context, especially Northern Europe, which raises questions about its generalisability to other regions or global scenarios. Given this limitation, future studies can broadly explore the relationship between traceability and MT-SSCM in different geographical regions to provide a more comprehensive understanding of traceability in global supply chains.

This study highlighted the pressing need for additional research dedicated to overcoming traceability-related obstacles. Given traceability’s important role in shaping firms’ MT-SSCM efforts, future studies should examine strategies for improving traceability and the circumstances that facilitate the adoption of particular MT-SSCM strategies. In addition, exploring the role of direct suppliers in extending traceability and sustainability to lower-tier suppliers is vital. Currently, many buyer firms focus their sustainability efforts only on their direct suppliers, largely ignoring the lower tiers. Hence, further research can provide valuable insights into and best practices for achieving sustainability goals in complex and multi-tiered supply chains.