The concept and its origins: questions and answers

Question 1

How was Digital Green Lean defined in the first paper?

Accepted Answer

In the 2023 concept paper, Gatell and Avella describe Digital Green Lean as a combination of Industry 4.0 and Lean Manufacturing with a focus on sustainability. It uses digital technologies to check and optimise production processes, reduce waste and minimise environmental impact, and it extends Lean as a business culture rather than replacing it.

Question 2

Had the term Digital Green Lean been used before 2023?

Accepted Answer

According to the authors, to the best of their knowledge the term had not been used in the bibliography before their review. The paper presents it as a concept emerging from the literature on Lean, Industry 4.0 and Circular Economy rather than as a rebranding of an existing model.

Question 3

What is Digital Green Lean Culture?

Accepted Answer

The concept paper proposes the specific term Digital Green Lean Culture as part of DGL. It describes a culture and leadership style that connects the core of Lean, people and continuous improvement, with state-of-the-art digital technologies and a focus on circularity and protecting resources.

Question 4

What research questions did the concept paper ask?

Accepted Answer

The paper asked two questions. RQ1: what is the impact of Industry 4.0 and Circular Economy on Lean Leadership and Lean Culture? RQ2: how can organisations integrate these concepts to drive operational excellence and sustainable growth? It answered them through a systematic literature review.

Question 5

How was the concept paper built methodologically?

Accepted Answer

It is a systematic literature review with an inductive, theory-building approach. The search ran in Web of Science and Scopus in four stages during 2021, producing 139 initial relevant papers, of which 82 were analysed in depth to answer the research questions.

Question 6

Where was the concept paper published?

Accepted Answer

The concept paper, 'Impact of Industry 4.0 and circular economy on lean culture and leadership: Assessing digital green lean as a new concept', by Ignacio S. Gatell and Lucía Avella, appeared in European Research on Management and Business Economics, volume 30 (2024), article 100232, available online in November 2023.

Question 7

Where was the maturity model published?

Accepted Answer

The maturity model paper, 'A maturity model for assessing Digital Green Lean leadership and culture implementation in manufacturing companies', by Gatell and Avella, was published online on 7 May 2024 in Total Quality Management & Business Excellence.

Question 8

What is the doctoral thesis about?

Accepted Answer

The thesis develops and gives exploratory empirical support to a Digital Green Lean framework centred on culture and leadership. It explains how Lean culture and Lean leadership must transform to accommodate Industry 4.0 and Circular Economy in process manufacturing, through three studies: a systematic literature review, a maturity model and a comparative case study of two aluminium producers.

Also asked as: Summarise the DGL thesis · Give me the abstract of the thesis · ¿De qué trata la tesis doctoral? · Resume la tesis

Sources: Doctoral thesis — Digital Green Lean (2026) · PDF page 13

Question 9

What are the three studies of the thesis?

Accepted Answer

Study 1 is the systematic literature review that builds the conceptual foundation. Study 2 develops the DGL culture and leadership maturity model. Study 3 is a comparative qualitative case study of two multinational aluminium producers in contrasting institutional contexts, one in Europe and one in the Middle East.

Also asked as: How is the thesis structured empirically? · ¿Cuáles son los tres estudios de la tesis?

Sources: Doctoral thesis — Digital Green Lean (2026) · PDF page 13

Question 10

Is DGL a new generation of Lean?

Accepted Answer

The thesis positions Digital Green Lean as a fourth-generation evolution of Lean Manufacturing, moving the field towards a digital-sustainable paradigm. It keeps the Lean foundations but extends them to include digitalisation and circularity.

Question 11

Why do the three transformations arrive together?

Accepted Answer

The thesis starts from the observation that operational excellence, technological change and sustainability are arriving simultaneously, each with distinct demands. Companies today do not get to choose which transformation to address first, so the challenge is to build the capabilities for all three without sacrificing operational performance.

Also asked as: Can companies choose which transformation to do first? · ¿Por qué llegan a la vez Lean, digital y circular?

Sources: Doctoral thesis — Digital Green Lean (2026) · PDF page 13

Question 12

What gap in the literature does DGL address?

Accepted Answer

The management literature had not adequately addressed the culture and leadership dimension of the convergence: how organisations build the human and organisational capabilities to implement Lean, Industry 4.0 and Circular Economy together without losing performance. The concept paper also found no article covering the impact of Industry 4.0 and Circular Economy on Lean leadership and culture.

Question 13

Should we do Lean first, then digital, then circular?

Accepted Answer

The thesis finds that organisations which sequence the transformations, first Lean, then digital, and finally circular, consistently fall short. Capability development for DGL is inherently parallel rather than sequential. This does not mean doing everything at once: priorities can be phased, but the three agendas are considered together from the outset.

Question 14

Is Lean a foundation for circular economy?

Accepted Answer

Yes, in the comparative case study. In both companies, established Lean capabilities worked as an enabling platform for Circular Economy adoption, regardless of institutional context. Lean provides measurement discipline, process stability, cross-functional problem solving and a continuous improvement orientation, which circular initiatives also need.

Question 15

Does the strength of the Lean base matter for DGL?

Accepted Answer

A strong Lean base helps, because it brings discipline, stability and problem-solving habits. The thesis does not present it as a stage to complete before the other agendas: capability development for DGL runs in parallel, and the strength of the Lean foundation in each area influences how quickly the digital and circular capabilities can be developed.

Question 16

What is Industry 4.0?

Accepted Answer

In the concept paper, Industry 4.0 is the fourth industrial revolution that arose in Germany in 2011 from a government initiative. It combines IoT devices and sensors, cloud computing, big data, artificial intelligence and machine learning, robotics, digital twins, additive manufacturing, augmented reality and cybersecurity, with a focus on data-driven decision-making, automation and optimisation.

Also asked as: Define Industry 4.0 · ¿Qué es la Industria 4.0?

Sources: Gatell & Avella — Digital Green Lean concept (2023 online / 2024 volume) · PDF page 1

Question 17

What is the Circular Economy?

Accepted Answer

The concept paper describes Circular Economy as an approach that optimises resource usage, reduces waste generation and decouples economic growth from resource depletion. It aims to keep products, components and materials at their highest utility and to design out waste and pollution from the start, using closed-loop material flows that are restorative and regenerative by design.

Also asked as: Define circular economy · ¿Qué es la economía circular?

Sources: Gatell & Avella — Digital Green Lean concept (2023 online / 2024 volume) · PDF page 2

Question 18

What is Lean Manufacturing?

Accepted Answer

The concept paper refers to Lean Manufacturing as a term coined by Krafcik in 1988 and popularised by Womack and colleagues in 1990, based on the Toyota Production System. It is a production paradigm proven to improve efficiency, quality, delivery, flexibility and customer satisfaction, and has evolved from a toolkit for waste reduction into a culture of values, principles and behaviours.

Question 19

How much could Industry 4.0 add to productivity?

Accepted Answer

The concept paper cites a World Economic Forum report (2019) according to which adopting Industry 4.0 could lead to a 4.5% increase in global GDP and a 15% increase in productivity by 2030. It is quoted as context for the paper, not as a result of the DGL research.

Question 20

What challenges does Industry 4.0 bring?

Accepted Answer

The concept paper mentions the need for workers with the skills to use and maintain new technologies, the risk of job displacement as automation spreads, and aspects such as developing Industry 4.0 know-how, securing financial resources, integrating employees into implementation and establishing an open, flexible culture.

Question 21

What challenges does the circular economy face?

Accepted Answer

The concept paper notes the lack of market incentives and supportive regulatory frameworks, issues related to intellectual property, taxation and public procurement, and a need for better metrics and indicators to measure the impact of circular initiatives.

Question 22

Why does circular economy need systems thinking?

Accepted Answer

The concept paper explains that Circular Economy requires a systems-thinking approach, with collaboration and coordination between stakeholders from design to disposal along the value chain, and innovative business models such as product-service systems, leasing, sharing and closed-loop supply chains.

Question 23

What are the benefits of Digital Green Lean?

Accepted Answer

The concept paper derives a value proposition from the literature: operational efficiency and cost savings, flexibility and adaptability, environmental sustainability, employee engagement, performance transparency through clear metrics, strategic direction and competitive advantage. These are benefits identified in the literature review, not guaranteed results for any single company.

Question 24

Give an example of digital technology supporting sustainability in DGL

Accepted Answer

The concept paper gives the example of sensors that track energy consumption, water usage and waste generation in real time, so organisations can identify areas for improvement and reduce environmental impact, and make data-driven decisions to optimise operations.

Question 25

What should an organisation do before adopting DGL?

Accepted Answer

The concept paper recommends assessing the current digital maturity to see where digital technologies can optimise operations, ensuring the skills to implement and manage them, and communicating the importance of Digital Green Lean to employees so that they are engaged and motivated.

Question 26

What is the role of leaders in DGL?

Accepted Answer

According to the concept paper, leaders who embrace DGL must be committed to sustainability and understand that it is a necessity for long-term success, not a nice-to-have. Lean Leadership plays a pivotal role, with coaching, empowerment and respect for people, and with employee engagement and development at its core.

Question 27

Are companies moving investment from Industry 4.0 to circularity?

Accepted Answer

The concept paper observes that, due to the high cost of some techniques, companies are moving resources initially dedicated to Industry 4.0 back to the operations line, trying to increase the circularity of their processes and reduce environmental impact. It is an observation from the review, not a universal rule.

Question 28

Was there a framework to measure the impact of I4.0 and CE on Lean companies?

Accepted Answer

As of the paper's knowledge cutoff in 2021, no established framework measured the impact of Industry 4.0 and Circular Economy on traditional Lean companies. The follow-up study found that existing maturity models covered either Industry 4.0 or sustainability in Lean, but none treated leadership and culture as the primary drivers, which led to the DGL culture and leadership maturity model.

Question 29

Do Lean companies have an advantage implementing Industry 4.0?

Accepted Answer

The concept paper reports that the reviewed articles argue that companies using Lean Manufacturing have a competitive advantage in implementing Industry 4.0, and that Industry 4.0 tools directly support the implementation of sustainability as a triple-bottom-line approach.

Question 30

How much research combines Lean, I4.0 and CE?

Accepted Answer

In the concept paper's review, only two papers combined the three concepts: one on how Industry 4.0 can integrate with Circular Economy and existing Lean environments, and one on how Lean and Industry 4.0 build competitive power through circular economy principles. Neither addressed leadership or culture.

Question 31

Which circular economy principles affect Lean culture and leadership?

Accepted Answer

The concept paper uses the operational principles of Circular Economy of the Ellen MacArthur Foundation: power of the inner circle (minimise resource use by reuse and recycling at every step), power of circling longer, power of cascade use (diversifying reuse across the value chain) and power of pure circles (uncontaminated material flows). It then maps how each affects Lean culture and leadership.

Also asked as: What are the inner circles and cascade use? · ¿Qué principios de economía circular afectan a Lean?

Sources: Gatell & Avella — Digital Green Lean concept (2023 online / 2024 volume) · PDF page 9

Question 32

What does cascade use mean for a production line?

Accepted Answer

Cascade use means diversifying reuse across the value chain. In the concept paper, lines should be ready to take recycled material from other products or manufacturing lines that could fit into them, which requires more flexibility while keeping robust processes to obtain quality at low cost.

Question 33

Which Lean culture traits are most affected by circular economy?

Accepted Answer

In the review, the maximum impact of circular economy lies in topics related to manufacturing and customers. The most affected Lean culture characteristics are continuous improvement, innovation, performance orientation and collectivism; for leaders, flow management, customer focus and zero defects or striving for perfection.

Question 34

How could DGL help a food factory with packaging waste?

Accepted Answer

The thesis and the DGL material do not include a case from food manufacturing or packaging, so there is no documented DGL result for that sector. What they do offer applies to process manufacturers in general.

DGL starts from where the organisation stands in culture and leadership maturity. It treats the pull between cutting waste and closing material loops as an Efficiency vs. Circularity tension to be managed on purpose. In the aluminium scrap case, this meant dedicated circular streams with their own performance expectations. It also develops Lean, digital and circular capabilities in parallel, not in sequence, and uses digital tools to make waste and variability visible in real time.

How this would look for packaging waste in a food plant is an adaptation that a scoped assessment would define. It is not a result reported in the sources.