Evaluating Shingo model alignment at Toyota Portugal: analyzing operational excellence in Industry 4.0 Open Access

In recent years, industries worldwide have undergone significant transformation, with Industry 4.0 (I4.0) spearheading technological advancements that are based in automated processes using tools like the Internet of Things (IoT), artificial intelligence (AI) and Big Data. These innovations have improved operational efficiencies, production quality, and organizational performance. However, while I4.0 emphasizes technological advancement, it often overlooks the role of human workers in driving innovation and organizational success (Kabzhassarova et al., 2021). This gap in human-centricity has led to the emergence of Industry 5.0 (I5.0), which tries to reintegrate human elements into technological progress, emphasizing human-centricity, sustainability and resilience as key pillars (Alves et al., 2023; Erp et al., 2024). I5.0 stresses the importance of human–machine collaboration, well-being, and empowerment of workers to sustain long-term competitiveness. In this context, the Shingo Model, a model for operational excellence, becomes increasingly relevant. The Shingo Model, founded on principles such as respect for individuals, continuous improvement and a focus on process, aligns closely with I5.0’s human-centric approach (Kelly and Hines, 2019). However, rather than specifically adopting the Shingo Model, many organizations may be applying its core principles without explicitly labelling it as such.

Toyota, renowned for its efficient production system and operational excellence, has long been a proponent of principles that align with the Shingo Model, particularly through its Toyota Production System (TPS). TPS emphasizes continuous improvement, respect for people and problem-solving at all levels of the organization (Liker, 2021; Ohno, 1988) – principles that are central to the Shingo Model. However, the question remains: does Toyota Portugal apply the Shingo Model without explicitly identifying it by name? This paper aims to explore the extent to which Toyota Portugal’s operational structure reflects the principles of the Shingo Model and how this alignment contributes to the pillars of I5.0. By examining Toyota Portugal’s practices through a series of 10 interviews, this study seeks to identify whether the company’s approach to operational excellence mirrors the Shingo Model’s foundational principles, such as empowering employees, fostering a culture of continuous improvement and ensuring quality at the source. Furthermore, it will assess how these practices support the pillars of I5.0, particularly human-centricity, sustainability and resilience, by promoting employee well-being, efficient resource use, and adaptability in an ever-evolving business environment. Ultimately, this research will contribute to a better understanding of how Toyota’s operational structure supports the broader goals of I5.0, even if it is not explicitly using the Shingo Model terminology. While this paper’s title references I4.0, it is important to note that there is currently no consolidated academic literature explicitly connecting the Shingo Model with I4.0 or I5.0. This represents a significant research gap. The present study is therefore exploratory in nature, using the case of Toyota Portugal – a company firmly rooted in the TPS and following an I4.0 strategy – to investigate how operational practices grounded in Shingo principles can intersect with the technological and human-centric ambitions of I4.0 and I5.0. In doing so, this research contributes to filling a theoretical void while grounding the discussion in a practical, real-world context.

This paper is structured as follows: after this introduction, Section 2 presents the literature review which explores the evolution from I4.0–5.0 and the Shingo Model’s principles. Section 3 outlines the case study approach, and Section 4 presents findings from the interviews, supported by evidence and an empathy map. The discussion, in Section 5, interprets these results, linking Toyota’s practices to the Shingo Model and I5.0. Finally, in Section 6, final remarks summarize key findings and theoretical and practical implications for organizations adopting Shingo and I5.0 principles.

As industries transition from the automation-driven paradigm of I4.0 to the more human-centered ethos of I5.0, engineering organizations face complex challenges in balancing technological innovation with workforce adaptability and well-being. This shift demands a reevaluation of how value is created – not only through systems and efficiency but through purposeful, people-focused collaboration. Section 2.1 explores the emerging workforce challenges associated with this transition, highlighting the evolving expectations placed on employees, the need for continuous upskilling and the integration of emotional intelligence within technical roles. Building on this, Section 2.2 considers how established operational excellence frameworks – particularly the Shingo Model – support this new industrial landscape.

I4.0 has fundamentally transformed the labor market by automating numerous processes through advanced technological tools such as the IoT, AI, Big Data and cyber-physical systems, among others (Kabzhassarova et al., 2021; Robert et al., 2020). While I4.0 was originally introduced with three core pillars – People, Processes and Technology – the human-centric aspect was largely overlooked (D’Orazio et al., 2020; Li et al., 2019; Powell, 2024). Organizations rapidly sought to implement technology to remain competitive, often neglecting the role of the workforce in this transition (Salvadorinho et al., 2020).

The ongoing shift toward I5.0 aims to address this gap by repositioning humans at the center of technological innovation (Barata and Kayser, 2023; Huang et al., 2022; Leng et al., 2022). The European Commission has clearly defined the three fundamental pillars of I5.0 (European Commission, 2022): human-centricity, sustainability and resilience. Human-centricity prioritizes employee well-being and promotes human-machine collaboration to enhance strategic skills (Erp et al., 2024; Hines, 2022; Mourtzis et al., 2022). In this way, technology should empower people, not replace them (Salvadorinho et al., 2025). Sustainability emphasizes environmentally friendly and socially responsible processes, aligning with corporate social responsibility (CSR) and long-term economic viability (Grybauskas et al., 2022; Piccarozzi et al., 2024). Beyond profit and productivity, I5.0 calls for responsible use of resources and the reduction of environmental impact (Erp et al., 2024). Resilience ensures that organizations develop agile strategies to navigate future uncertainties, including investments in workforce skill development, robust digital infrastructures and flexible work models (Golovianko et al., 2022). Therefore, it represents a shift from pure automation and optimization toward a more human-centric, sustainable and resilient industrial ecosystem.

Despite rapid technological advancements, the role of human talent remains irreplaceable – especially in light of workforce trends like the Great Resignation and Quiet Quitting, which highlight the growing importance of engagement, purpose and well-being in retaining skilled employees (Salvadorinho et al., 2025). The Great Resignation, which began before the COVID-19 pandemic despite ongoing debates regarding its origins, highlighted the consequences of mass workforce exits, leading to a significant loss of tacit knowledge – the unstructured, experience-based knowledge retained by employees (Kuzior et al., 2022; Serenko, 2022). Conversely, the more recent Quiet Quitting phenomenon involves employees remaining within organizations but contributing minimal value (Serenko, 2024). This trend poses substantial risks to organizational innovation and agility, as disengaged employees hinder the company’s ability to adapt and thrive in a rapidly evolving market (Liu-Lastres et al., 2024).

Given these challenges, it is imperative for organizations to develop strategies that enhance employee retention, foster engagement and safeguard tacit knowledge (Salvadorinho et al., 2024; van Dun and Kumar, 2023). Implementing effective workforce management policies that align with the principles of I5.0 will be crucial for sustaining long-term competitiveness and innovation (Salvadorinho and Teixeira, 2021).

The Shingo Model is a framework for operational excellence that helps organizations achieve continuous improvement and long-term success (Shingo Institute, 2021). Named after Shigeo Shingo, a key contributor to the Toyota Production System, the Shingo Model is built around five key elements – tools, results, systems, principles and culture – with guiding principles at its foundation and organizational culture at the center, driving sustainable excellence across all levels (Shingo Institute, 2021). Rather than focusing solely on methodologies, the Shingo Model is built on fundamental principles (Figure 1) such as:

• respect every individual;

• lead with humility;

• seek perfection;

• embrace scientific thinking;

• focus on process;

• assure quality at the source;

• improve flow and pull;

• think systemically;

• create constancy of purpose; and

• create value for the customer (Kelly and Hines, 2019; Sá et al., 2023).

In today’s fast-paced and competitive business environment, the Shingo Model is more relevant than ever, particularly in I5.0 landscape. By providing a structured approach to lean transformation, it helps companies eliminate waste, improve efficiency, and enhance product and service quality.

A core principle of the Shingo Model is respect for every individual, which directly connects with I5.0’s emphasis on human-centricity. Instead of fully replacing workers with automation, I5.0 focuses on collaboration between humans and advanced technologies like artificial intelligence and robotics (Erp et al., 2024; Ghobakhloo et al., 2023). The Shingo Model reinforces this by advocating for a culture of empowerment, where employees are encouraged to contribute with ideas, and take ownership of continuous improvement efforts (Hines, 2022). Additionally, the principle of leading with humility ensures that leadership is open to learning, values employee input, and creates an inclusive environment where all individuals contribute to the organization’s success. Sustainability, another key pillar of I5.0 (Piccarozzi et al., 2024), aligns with the Shingo Model’s principles of assuring quality at the source and creating value for the customer, both of which contribute to long-term sustainability. By ensuring quality from the beginning of the production process, companies reduce defects, and optimize resources, leading to more efficient and eco-friendly operations (Grabowska et al., 2022). Furthermore, focusing on customer value encourages organizations to develop sustainable products and services that meet long-term needs rather than short-term gains, reinforcing their commitment to environmental and social responsibility (Subedi et al., 2023). I5.0 places a strong emphasis on resilience, enabling businesses to adapt and thrive in an unpredictable environment (Mourtzis et al., 2022; Sharma and Gupta, 2024). The Shingo Model reinforces this through key principles such as seeking perfection, which drives continuous process improvement and excellence, and embracing scientific thinking, which fosters data-driven decision-making and systematic problem-solving. Additionally, focusing on processes helps organizations develop strong, repeatable systems that ensure consistency and high-quality outcomes, while thinking systemically allows companies to understand the interconnections within their operations and respond effectively to disruptions (Hines et al., 2020).

However, there is a lack of literature on this model, particularly regarding its interaction with the digital paradigm. The model is more widely recognized in the USA (Shingo Institute, 2021), and its connection with the pillars of I5.0 has not been studied.

The case study company operates within the automotive industry, focusing on the production of vehicles, and embraces the TPS, an established operational philosophy developed by Toyota, which has become a global benchmark for lean manufacturing (Monden, 1984). TPS aims to maximize value creation by systematically eliminating waste (muda), fostering a culture of continuous improvement (kaizen) and promoting deep respect for people throughout all organizational levels.

The organization’s system is built upon two foundational pillars: Just-in-Time (JIT) and Jidoka. Just-in-Time ensures that each process step produces only what is needed, in the necessary quantity, and precisely when required, reducing inventory and improving flow efficiency. Jidoka, often referred to as “automation with a human touch,” empowers workers and systems to immediately identify and respond to abnormalities, preventing defective products from advancing in the production line. Together, these pillars create a robust framework that integrates technical excellence with human-centric practices, supporting operational stability, high product quality and continuous learning.

The organization under study is structured around key production sectors – Logistics, Welding, Painting, Assembly and Inspection – each managed by Group Leaders responsible for human resources and strategic decisions. Team Leaders operate with more limited decision-making authority but play a crucial role in coordinating operational activities, training workers, and ensuring production flow. Team Members, forming the largest workforce segment, are directly involved in production processes and are distributed across these sectors. A schematic representation of the organizational structure is presented in Figure 2.

A variety of standardized tools are used within the organization to support work analysis and process improvement. These include:

• the Standardized Work Recording Sheet (SWRS), which categorizes tasks based on value and supports takt time analysis;

• the Standardized Work Combination Table (SWCT), which identifies inefficiencies through detailed time breakdowns; and

• the Standardized Work Chart (SWC), or Spaghetti Diagram, which allows visualizing operator and material movement to improve layout and reduce waste.

Complementary tools such as the Work Step Sheet (WSS) and Element Work Sheet (EWS) ensure consistent task execution and training effectiveness, while the Yamazumi Chart assists in balancing workloads across stations, enabling a more efficient distribution of tasks.

Regarding quality management, the organization applies a range of structured tools and methodologies. Quick PDCA is used for the rapid resolution of recurring issues through simplified problem analysis. The CAR (Corrective Action Report) is triggered by internal audits or customer complaints and incorporates root cause analysis, most notably through the 5 Whys and Ishikawa diagrams, complemented by photographic evidence and a clear allocation of responsibilities. The A3 Problem Solving methodology is reserved for more complex or high-impact issues, promoting strategic thinking and structured implementation. Continuous improvement is further supported through Kaizen initiatives, Quality Control Circles (QCC) and Jishuken activities (continuous improvement activity led by company’s specialists that involves employees from different departments working together to solve a specific problem on the shop floor) – all of which foster employee engagement, cross-functional collaboration and on-the-ground problem-solving through experiential learning. These practices reflect a proactive and participative approach to operational improvement, grounded in standardization, employee involvement and continuous learning. Through Gemba Walks, which involve regular visits to the shop floor, the organization applies the Toyota principle of Genchi Genbutsu (“go and see for yourself”), enabling direct observation of operations and facilitating informed decision-making based on first-hand insights. This approach reinforces a culture of presence and accountability at all levels of the production system.

Moreover, the organization places significant emphasis on structured communication across departments, facilitated by a series of daily meetings, each with a distinct purpose. The Morning Meeting begins with light exercises followed by a summary of the day’s production goals and key individual tasks, setting a tone of discipline and preparedness. The Asakai Meeting, involving all production sectors, serves as a platform for reviewing current issues, identifying defects that may have crossed sectoral boundaries, engaging in brainstorming for improvements and presenting the production plan for the rest of the day. The Seiriichi Meeting is more specific, focused on monitoring whether corrective actions are effectively resolving previously identified problems, thus ensuring the sustainability of problem-solving efforts. Finally, the Yuiichi Meeting summarizes the day’s production performance and sets the stage for the following day, reinforcing alignment and continuity in operations. These communication routines contribute to a shared understanding of priorities, strengthen interdepartmental coordination, and reinforce a problem-solving mindset throughout the organization.

This study uses a qualitative case study methodology, centered on Toyota Portugal as the single case. The case study approach is particularly well-suited for this research, as it enables an in-depth exploration of a complex organizational setting within its real-world context (Azungah, 2018; Denzin and Lincoln, 2018). Given that the central research question investigates whether Toyota Portugal applies the Shingo Model principles without explicitly referencing them, this method allows for nuanced understanding of both formal and informal practices, values and systems.

The case study was designed to examine the extent to which Toyota Portugal’s operational structure reflects the principles of the Shingo Model and how this potential alignment supports the pillars of I5.0. Toyota Portugal presents a highly relevant case due to its well-established implementation of the TPS. Although the organization does not explicitly reference the Shingo Model, both frameworks share foundational principles – such as process focus, and pursuit of perfection. By examining this implicit alignment, the study aims to understand whether the company’s operational culture and practices reflect the thinking promoted by the Shingo Model, and how this alignment contributes to the broader human-centered and resilient vision of I5.0.

To gather detailed data, the study conducted 10 semi-structured interviews with employees from various departments, with different roles. This method enabled the collection of diverse perspectives while allowing flexibility to explore themes emerging during the conversations (Azungah, 2018; Denzin and Lincoln, 2018). Interview questions were designed to elicit information about daily practices, decision-making processes, values and operational routines – particularly those that may align with the Shingo Model’s guiding principles. To strengthen the validity and reliability of the data collection process, the interview script underwent a two-step validation. First, it was reviewed by two academic experts in lean management and operational excellence to ensure conceptual alignment with the Shingo Model principles and relevance to the I4.0/I5.0 framework. Second, a pilot interview was conducted with a Toyota Portugal employee not included in the final sample, allowing refinement of wording and sequencing to avoid ambiguity and ensure comprehension. Reliability was supported through a consistent interview protocol applied across all respondents, coupled with the use of semi-structured questions that balanced comparability with flexibility for probing deeper insights. Inter-coder reliability during content analysis was achieved by having two independent researchers code an initial subset of interviews, resolving discrepancies through discussion to enhance consistency and reduce interpretive bias. The interview data were synthesized into evidence tables, which highlighted specific tools, behaviors, and practices connected to each Shingo principle. In parallel, each identified practice was also mapped to the corresponding I4.0 evidence (focus on technologies applied) and I5.0 pillar it potentially supports, thus creating a dual analytical lens: one grounded in organizational excellence, and the other in future-oriented socio-technical transformation.

In addition to the interviews, participant observation was conducted to gain a deeper understanding of the standard work and leadership behaviors of group leaders in their daily interactions with the team. This immersive approach allowed for a better understanding of the processes and practices being discussed in the interviews. Furthermore, a journey map was created to visually represent the flow of operations, highlighting key touchpoints where leadership practices, employee involvement and technological tools intersect.

To conduct efficient data collection, semi-structured interviews were carried out, as described in  Appendix 1Table A1, which outlines the questions designed to assess the company’s organizational excellence based on the ten principles of the Shingo Model. The interview script was structured to cover each of these principles individually. Prior to each interview, participants were informed about the purpose of the study and explicitly asked for their consent to record the conversation, ensuring ethical compliance and voluntary participation. A snowball sampling technique was employed to identify interviewees, where initial participants recommended colleagues with relevant knowledge or experience regarding the application of the Shingo Model within the company. This approach facilitated access to informed participants and ensured that insights were gathered from individuals actively engaged with the principles under investigation. Table 1 provides a comprehensive overview of the interviewees’ demographic and professional profiles, focusing on their age range, responsibilities, and seniority within the company. Most interviewees are included in the 18–30 age range, indicating a relatively young workforce, while only two individuals are within the 45–65 range. The average company seniority across interviewees is approximately 11.7 years, with values ranging from 2 to 38 years. This diversity ensures a broad spectrum of perspectives, from newcomers to highly experienced professionals, enriching the insights gathered during the interviews.

The interviewees represent a variety of roles across different organizational functions, particularly within quality and engineering domains. Several respondents are directly involved in quality management activities, such as Quality Assurance, Kaizen and QCC (Quality Control Circles), highlighting the company’s emphasis on continuous improvement and standardization. The inclusion of process engineers, a project manager and a group leader also illustrates the interdisciplinary nature of the team involved in initiatives to promote the organizational excellence. This range of roles and responsibilities strengthens the validity of the qualitative data collected and provides a solid foundation for analyzing the organization’s approach to quality management and digital transformation.

In addition to the interviews, participant observation was also conducted to better understand the standard work of group leaders and how leadership behaviors are expressed in daily operations.

The qualitative data obtained from the 10 semi-structured interviews were examined through content analysis, which allowed for a systematic exploration of patterns, meanings and thematic structures within the textual data (Nowell et al., 2017; Vaismoradi et al., 2013). Initially, a deductive coding scheme was developed based on the ten core principles of the Shingo Model. This was complemented by inductive codes that emerged from repeated readings of the transcripts. Two researchers independently coded a subset of the interviews to establish intercoder reliability, and discrepancies were resolved through discussion to minimize interpretive bias. The final coding framework was then applied consistently across all transcripts. The analysis focused first on identifying explicit and implicit references to behaviors, tools and practices associated with each Shingo principle. To visualize the qualitative evidence, coded excerpts were categorized into tables mapping specific practices to the corresponding principles observed within Toyota Portugal’s operations. In addition, the interviews were reviewed for references to I4.0 technologies – such as automation, connectivity and data-driven processes – and these were mapped against the five pillars of I5.0 to evaluate their alignment with emerging human-centric and sustainable priorities. Each technology or practice identified was assessed for its contribution to these pillars. Regarding the inclusion of Likert-scale responses embedded in the interview script, these were used as a complementary technique to reflection and structure discussion, rather than as standalone quantitative measures. While descriptive results from these responses were collected, they were not subjected to statistical analysis and were instead used to triangulate and support thematic interpretations from the qualitative content analysis. In parallel, a journey map was created to visually represent the group leader’s workflow, highlighting key touchpoints, decision-making moments and leadership practices throughout daily operations. The journey map highlighted the interactions between leadership and employees, focusing on moments where operational practices and leadership values intersect, providing further context to the interview data.

Based on the interviews conducted, it was possible to develop a qualitative analysis focused on understanding the perspectives of the selected group of employees regarding the pillars of the Shingo Model. Table 2 presents a structured summary of the main insights drawn from the interviewees’ responses, which reflect varying degrees of alignment with each of the ten guiding principles of the model. In addition to identifying clear evidence, the analysis also allowed the identification of absence of evidence, where there was no reference to specific Shingo principles during the interviews. This dimension provides valuable insight into areas where the organization may need to further develop awareness or implementation efforts. The table also includes references to concepts associated with I4.0 and I5.0, based on whether the responses implicitly or explicitly mentioned technologies, approaches or values related to these paradigms.

The principle “Respect Every Individual” is supported by several examples provided by the interviewees, such as participation in improvement activities (Kaizen, QCC and Jishuken), encouragement of autonomy, and openness to employee input in problem-solving processes. However, the analysis also reveals an absence of references to more human-centric aspects, such as individual recognition or inclusive decision-making. Activities that promote individuality are not carried out on a regular basis. This suggests that, while technical engagement is evident, the broader cultural dimension of respect may require further reinforcement.

Regarding “Lead with Humility,” the evidence emphasizes alignment with the Toyota Way thinking philosophy, particularly in the form of leadership presence and proximity on the shop floor. Furthermore, respondents expressed a sense of difficulty in transitioning from suggestion to actual implementation of proposed ideas. This may indicate a leadership style that is more directive than participatory.

Concerning the “Seek Perfection” principle, interview responses highlight TPS training, multi-skilling initiatives and participation in QCC, Jishuken and Kaizen activities as prominent practices that contribute significantly to organizational improvement. On the other hand, an identified limitation is the lack of digital solutions in certain processes, with some critical information still being recorded manually.

For “Embrace Scientific Thinking,” various mechanisms are in place to support it. In relation to quality practices, respondents highlighted the use of QCC, PDCA, CAR, follow-up procedures and A3 projects. However, several participants also noted a perceived absence of a safe-to-fail environment, which may act as a barrier to innovation and experimentation – both essential components of scientific thinking.

In the case of “Focus on Process”, respondents acknowledged the importance of standardization and procedural compliance – citing tools such as Toyota Standard Work Sheets (SWRS, SWCT, Moving Line, WSS, EWS, Yamazumi). However, the absence of deeper evidence suggests potential gaps in fostering a culture of continuous improvement beyond compliance. From an I4.0 perspective, some level of process digitalization was observed, particularly through the use of VBA (Visual Basic for Applications) programming, which contributes to improving documentation efficiency.

The “Assure Quality at the Source” principle is moderately represented through references to quality control mechanisms and active participation in assurance tasks, such as sample-based tightening confirmation, the Andon System, Stop-Call-Wait methodology, Quality Gates, Pokayokes, the Built-in-Quality philosophy and TPS training. However, there was limited mention of real-time problem solving at the moment of alert occurrence, or the application of structured root cause analysis techniques – both central to this pillar – despite the presence of some automated quality checks powered by VBA.

For “Flow and Pull Value” there is direct evidence suggesting that lean flow principles, such as takt time, pull systems and value stream alignment, are embedded within the organizational mindset. A Pull System integrated with ERP (SAP) is in place. However, interviewees also pointed out excessive delays and bottlenecks, particularly in the Painting area, which may be undermining flow efficiency.

The principle “Think Systemically” was mentioned primarily in the context of cross-functional collaboration. Interviewees referred to structured routines such as Morning Meetings, Asakai, Seriichi and Yuiichi, which aim to foster interdepartmental communication. Nevertheless, gaps were identified in the effective dissemination and coordination of continuous improvement initiatives, suggesting that systemic alignment remains a challenge.

When considering “Create Constancy of Purpose,” several responses reflect an awareness of the organization’s long-term objectives, particularly in relation to quality. Practices such as Genchi Genbutsu, Quality Committees and biannual company-wide status presentations were cited as efforts to promote strategic alignment. However, structured communication regarding vision consistency across different functions appears to be lacking.

Finally, in terms of “Create Value for the Customer,” there were references to activities such as Satisfaction Surveys and FTR (Field Technical Reports). Still, the evidence does not strongly reflect a customer-centric mindset as a core driver of internal processes, justified by the limited analysis from costumer’s feedback.

References to I4.0 concepts were identified throughout the study, particularly in the use of digital tools, structured problem-solving methodologies and process-oriented practices. When analyzing the foundational pillars of I5.0, it became evident that the principle of Resilience was the most prominent, primarily due to the strong organizational focus on process stability and adaptability.

Focusing on the answers to the interview questions, which were evaluated on a Likert scale from 1 to 5, it was possible to conduct an analysis that resulted in the construction of Table 3 and Figure 3 (boxplots for each principle).

The analysis of responses, aligned with the Shingo Model principles, reveals a moderately developed organizational culture, with identifiable strengths and areas for improvement. The median values across the ten principles suggest a relatively consistent perception of practices, although some principles are more solidly established than others. Notably, the principles of “Respect Every Individual” (specifically Respect_Every_Individual_2 in Figure 3), “Create Constancy of Purpose,” “Create Value for the Customer” and “Seek Perfection” received the highest median score (4.0), highlighting a human-centered strategic orientation. This suggests a deep organizational commitment to people – both employees and customers – and a shared awareness of the importance of delivering high-quality outcomes, even if the notion of “customer” was not always explicitly articulated.

In contrast, “Lead with Humility,” “Flow and Pull Value,” “Think Systemically” and “Embrace Scientific Thinking” showed the lowest median scores (all at 3.0), indicating that these areas of cultural maturity require further development. Although leadership maintains a visible presence on the shop floor, feedback indicates that opportunities for frontline employees to actively participate or share input may be limited – elements that are essential to humility-driven leadership. Similarly, the low rating for “Flow and Pull Value” (median 3) is related to ongoing inefficiencies and bottlenecks, suggesting operational issues despite the formal implementation of pull-based systems. The relatively weak performance in “Think Systemically” reflects fragmentation across departments, where interdepartmental communication mechanisms exist but lack integration and strategic cohesion. Additionally, the perception of “Embrace Scientific Thinking” at 3.0 further suggests that even though structured problem-solving exists, the absence of a safe space for experimentation may limit innovative capacity and employee engagement.

The principle “Assure Quality at the Source” was also assessed and received a median score of 3.0, indicating a moderate level of maturity. While mechanisms to detect and address quality issues early are present, there is still room to strengthen the technologies used across operational practices. Furthermore, this aligns with recent performance indicators, which show that final product quality metrics have not been consistently positive, reinforcing the need for improvement in this area.

To analyze a relevant example of leadership practices within the company and to better understand the nature of daily management activities, it was considered appropriate to develop a journey map. For this purpose, the daily routine of a Group Leader (GL) was examined, as this role involves the coordination of a significant number of employees. Table in  Appendix 2 presents the Group Leader Experience Journey Map, which outlines the GL’s daily tasks and was constructed based on operational reports provided by the company.

By mapping the Journey Expectations (agenda, technological requirements, and location of activities), alongside the employee’s experience and emotional perceptions of day-to-day tasks, several challenges and improvement opportunities were identified. These include: “Preparing all data for the meeting,” “Time-consuming meetings,” “Difficulty in finding key data,” “Lack of automated analysis” and “Manually confirming production status.” Following a more detailed analysis and a dedicated brainstorming session with Group Leaders, it was possible to estimate the average time distribution across their daily responsibilities, as summarized in Table 4.

It is evident that a significant portion of the Group Leaders’ time is allocated to administrative work and meetings, which contributes to a sense of dissatisfaction and operational inefficiency. From a process perspective, a substantial amount of time is also required, not only because it represents a focus of the role, but also due to the lack of technological tools capable of streamlining data analysis and supporting more efficient decision-making. This highlights the potential benefits of digital transformation in enhancing both productivity and job satisfaction in leadership roles.

The interviews provided valuable qualitative insights into the organization’s alignment with the Shingo Model, revealing both strengths and opportunities for development. While certain principles, such as respect for individuals and quality assurance, are partially reflected in current practices, others – particularly systemic thinking, humility in leadership and lean flow – require further development. Furthermore, the limited presence of I4.0/I5.0 references indicates a need for greater awareness and integration of digital and human-centric technologies in quality and operational strategies.

Based on the interview results, it was possible to draw several insights, particularly by stratifying the analysis into two dimensions: the process and the individual.

An assessment of Table 2 reveals multiple forms of evidence aligned with the ten principles of the Shingo Model. The organization clearly demonstrates the use of numerous tools that support structured processes, particularly through the application of problem-solving methodologies. However, there is a gap in technological development, as its digital transformation is not yet mature, and current systems and technologies remain limited.

Table 3 further highlights how the organization approaches individuals and how it manages processes. While there is evidence of a positive organizational culture and the presence of operational tools, there is a lack of integrated systems and insufficient interdepartmental communication. Figure 4 illustrates the distinction between the Shingo Model’s guiding principles and the median scores obtained from the corresponding interview responses across the various pillars of the model.

From this analysis, it becomes evident that the principles related to individuals and value alignment with the organization demonstrated a notably stronger performance (median – 4.0) when compared to those associated with processes and continuous improvement (median – 3.0). While there is considerable evidence of efforts in both areas, the limited use of supporting technologies suggests an underdeveloped digital infrastructure, which is essential for enhancing organizational performance and enabling more effective continuous improvement practices.

The analysis reveals that the group leaders’ time is primarily dedicated to process-related activities, as is typical within the TPS, which places a strong emphasis on process optimization, waste reduction and efficiency (Chiarini and Vagnoni, 2015). In this context, TPS inherently prioritizes the improvement and management of processes (Monden, 1984), which leaves less time for focusing on people-oriented activities. This focus on processes is reflected in the significant amount of time each group leader spends on operational tasks aimed at enhancing workflow and standardizing practices. However, when comparing the results to the Shingo Model’s principles, particularly those centered on people – such as Respect Every Individual and Create Constancy of Purpose – the organization scores more favorably in people-centric principles. These principles, which are at the heart of the Shingo Model, emphasize the importance of leadership, employee engagement and fostering a culture of respect and continuous development (Kelly and Hines, 2019), aligning with the human-centricity pillar of I5.0 (Alves et al., 2023; Golovianko et al., 2022; Kolade and Owoseni, 2022). Yet, there is a notable paradox: despite the organization’s stronger alignment with people-centric principles, group leaders spend significantly less time on activities that directly support people development. Instead, much of their time remains focused on process-related tasks. This disconnect highlights an opportunity to better balance the emphasis on process improvement with a stronger commitment to people-oriented leadership practices, integrating the human-centered focus of the Shingo Model into the traditionally process-driven framework of TPS. Moreover, principles such as Systemic Thinking and Scientific Thinking – central to the Shingo Model’s holistic approach – score lower in the organization. These principles require structured, data-driven methodologies, cross-functional collaboration and organizational investments in digital infrastructure, training, and standardized processes, which appear less embedded in day-to-day operations. This suggests that while cultural values and leadership behaviors effectively promote people-centric principles at relatively low resource cost, deeper systemic and scientific approaches demand more substantial organizational commitment and resources. Ultimately, while TPS’s focus on process improvement dictates much of the group leaders’ daily responsibilities, Toyota Portugal has a clear opportunity to enhance its application of people-oriented principles by dedicating more time and resources to leadership practices that foster engagement and respect. Doing so could strengthen long-term learning, continuous improvement and innovation without sacrificing the operational efficiencies that TPS is known for.

When the results are analyzed through the lens of the I5.0 pillars – human-centricity, sustainability and resilience – it becomes evident that Toyota Portugal demonstrates strong cultural alignment with the first pillar, particularly in the principles of Respect Every Individual and Create Constancy of Purpose. These practices reinforce a people-first culture that empowers employees, supports their development and fosters engagement – conditions that are essential for human-centric transformation in the I5.0 era. In terms of Sustainability, while the case study did not explicitly focus on environmental metrics, several Shingo-aligned practices such as quality at the source, waste reduction and continuous improvement contribute indirectly to sustainable outcomes by minimizing rework, optimizing resource use and enhancing process stability. This suggests that the integration of Shingo principles within TPS can provide a foundation for broader environmental and social sustainability goals, even when these are not the explicit operational focus. Regarding Resilience, the results indicate that Toyota Portugal’s strong emphasis on standardized processes, structured problem-solving and adaptive leadership behaviors create a robust organizational framework capable of responding to operational challenges. However, the lower maturity scores for principles such as Embrace Scientific Thinking and Think Systemically suggest that resilience could be further strengthened through deeper cross-functional collaboration and greater tolerance for experimentation.

From a technological adaptation perspective, the evidence points to a partial alignment with I4.0 readiness. The presence of some digital tools – such as VBA-based automation, ERP integration and limited process digitalization – demonstrates an awareness of the role of technology in supporting operational excellence. Nevertheless, the relatively low integration of advanced I4.0 technologies such as real-time analytics, IoT-enabled monitoring and collaborative robotics limits the speed and agility with which the organization can implement changes, solve problems and capture new value. Embedding Shingo principles into the adoption of such technologies could ensure that digital transformation initiatives remain aligned with human-centric values, using technology as an enabler rather than a replacement for human decision-making.

Overall, the interplay between cultural alignment to Shingo principles and the gradual integration of digital tools suggests that Toyota Portugal has a solid cultural base upon which to build a more comprehensive I5.0 strategy. By pairing technological adaptation with a deliberate emphasis on human-centricity, sustainability and resilience, the organization can move toward a more balanced socio-technical system capable of thriving in the evolving industrial landscape.

One of the primary contributions of this study is the exploration of how Toyota Portugal’s operations align with the Shingo Model principles. While Toyota is globally recognized for its TPS and its focus on operational efficiency, this study reveals a layer of Toyota’s organizational culture that resonates with the Shingo Model’s cultural enablers. Toyota Portugal demonstrated a strong alignment with these principles, scoring a favorable median (4.0 out of 5.0) in terms of cultural enablers and enterprise alignment. These principles are essential for creating a workplace that respects individuals, fosters employee development, and prioritizes leadership humility. They also emphasize the alignment between employee purpose and enterprise values, ensuring that employees feel connected to the organization’s mission and vision. This alignment not only strengthens internal engagement but also supports the creation of customer value, as it encourages employees to work towards common goals that benefit both the organization and its customers. However, while there is clear evidence of a positive organizational culture, the analysis highlights that group leaders spend more time on process-related tasks, consistent with TPS’s focus on operational efficiency, rather than activities that directly nurture human potential. This indicates a gap in the integration of people-centric leadership practices within Toyota Portugal’s TPS framework, which could be enriched by incorporating the Shingo Model’s human-centered leadership focus more comprehensively.

This study contributes to the theoretical understanding of I5.0, particularly the integration of human-centric technologies within Toyota Portugal’s operational structure. I5.0 emphasizes a more human-centered approach to digital transformation, where digital and human-centric technologies converge to support both technological innovation and the development of human capabilities. The study’s findings indicate that Toyota Portugal is already integrating people-oriented principles, yet its digital transformation is still evolving, with a limited integration of I4.0/I5.0 technologies in its current systems. The absence of advanced technologies hinders the company’s ability to achieve real-time decision-making, agile problem-solving and data-driven continuous improvement, which are central to I4.0.

Integrating the Shingo Model’s guiding principles offers a valuable pathway toward this transformation. Principles such as Respect Every Individual and Create Constancy of Purpose help align employee purpose with enterprise values, increasing intrinsic motivation and supporting the creation of meaningful customer value. Combined with the socio-technical vision of I5.0, this integrated approach paves the way for more agile, resilient and innovative workplaces.

To support this shift, several best practices emerge:

• Balance process and people: While process efficiency remains critical, organizations should ensure leaders also dedicate time to human development – mentoring, coaching and empowering employees to grow and contribute meaningfully.

• Adopt human-centric technologies: Leverage I4.0 tools such as collaborative robotics, real-time analytics and AI not just for automation, but as enablers of smarter, more supportive work environments that amplify human potential.

• Foster cross-departmental collaboration: Break down barriers and create open channels for communication and shared problem-solving. This collective approach enhances both process improvement and employee alignment.

• Reframe continuous improvement through people: Involve employees actively in problem-solving initiatives. Their insights, experiences and creativity are essential to achieve sustainable improvements.

• Create safe-to-fail environments: Encourage experimentation, reflection, and learning. Psychological safety is crucial for innovation and supports the kind of adaptable culture needed in the I5.0 era.

• Invest in learning and leadership: Offer development opportunities that blend technical skill-building with leadership and interpersonal growth. This strengthens resilience and helps employees thrive amidst change.

• Align strategic goals with human-centric values: Ensure organizational objectives reflect both process excellence and people development. Regularly review these goals to maintain a cohesive and forward-thinking direction.

By embracing these practices, organizations can bridge the strengths of TPS with the cultural depth of the Shingo Model and the forward-thinking humanism of I5.0. The result is not merely improved efficiency, but a transformative shift toward empowered people, continuous innovation, and a dynamic workplace where human potential and technological advancement are not only integrated but constantly pushing each other to new frontiers of excellence.

To strengthen I4.0/I5.0 maturity, Toyota Portugal should embed technology more deliberately into TPS workflows. Priority actions include: introducing IoT sensors and real-time dashboards for faster decision-making; deploying collaborative robotics to reduce repetitive work; using AI-driven analytics for predictive maintenance and defect prevention; and expanding digital training platforms that integrate technical and cultural development. These measures, applied with a people-centered approach, would enhance efficiency, resilience, and alignment with Shingo principles while ensuring technology serves as an enabler rather than a replacement for human contribution.

This study offers a valuable glimpse into how Toyota Portugal aligns operational excellence with the human-centered principles of the Shingo Model. However, its scope is limited to a single organizational context and moment in time. Future research could explore how these practices evolve across sectors and deepen our understanding of how emerging I4.0 and I5.0 technologies can amplify – not replace – human potential. Longitudinal studies and cross-industry comparisons would help uncover how organizations can balance efficiency with meaning, creating workplaces where innovation, growth and purpose thrive together.