Identifying critical challenges to lean construction adoption

1. Introduction

The idea and application of lean management as early as the 1990s and its astounding success in the manufacturing sector have motivated management and practitioners to apply lean management practices in the construction sector as well (Koskela et al., 2019; Nwaki et al., 2021; Howell and Ballard, 1994). The present issues in the construction sector are a result of traditional project management lacking a comprehensive underpinning theory in three areas. Lean construction (LC) is an invention that emerged as a result of established methods’ failure to address several recurring, widespread issues on projects. From Koskela’s groundbreaking work, LC has progressed and expanded. He put up a well-rounded theory that included ideas and procedures from the Toyota Production System (TPS) (Ballard and Tommelein, 2012; Biton and Howell, 2013). Researchers claim that the implementation of LC management can revolutionize the construction industry (Ballard et al., 2020; Karaz et al., 2021). The most notable outcomes of LC implementation are cost savings (Awad et al., 2021), profitability (Bayhan et al., 2021), productivity (Hamzeh et al., 2021; Awad et al., 2021), project duration (Orlov and Kankhva, 2021), project quality (Xing et al., 2021), safety (Abu Aisheh et al., 2021), sustainability (Bertagnolli et al., 2021), information sharing and collaboration among participants (Ong and Pheng, 2021), inventory management (Zahraee et al., 2021), job satisfaction (Al Balkhy et al., 2021) and project scheduling and predictability (Sbiti et al., 2021).

The implementation of LC was received with positive sentiments across several areas, including the USA, South America, the UK and European countries (Al Balkhy et al., 2021; Habibi Rad et al., 2022; Sarhan and Pretlove, 2021; Schimanski et al., 2021). LC has various advantages for the construction industry, including efficient resource management and use, on-time project delivery and environmental sustainability. The adoption of LC in Nigeria and its value to communities, contractors and end-users were examined in a study where scholarly reports and publications revealed that only a small number of working professionals, primarily in Lagos, Abuja, Port-Harcourt, etc., had correctly embraced the lean building principles. Limitations in construction employees’ knowledge, exposure and educational attainment have been noted (Babaremu et al., 2022). In Oman, study data was gathered using an online questionnaire survey following a quantitative research methodology. According to the poll, half of the construction professionals and one-third of them have a higher level of awareness regarding LC practices. With a strong consensus on applicability and acceptability, more than one-third of construction organizations are embracing LC principles. They also understand that time investment is important for successful implementation and to realize advantages. According to the study’s findings, the primary benefit of applying LC principles during the design and construction phases in the Omani construction industry is the decrease in project delivery time and construction site waste (Shah et al., 2021). If the lean production method is properly implemented, the plastics industry in Lebanon has the potential to grow to be one of the country's most successful industries when compared to other industries. This is possible if the company offers the proper education and training programs to the appropriate staff members to raise their awareness of the system and help them fully comprehend lean and its advantages, help them overcome their lack of vision and secure the support and commitment of top management. Managers need a plan to back up their efforts to implement lean (Hamzeh et al., 2016). A scenario of integration and proactive implementation of the lean system will result from training. Additionally, top management must encourage and support their employees while they work efficiently and effectively (Nassereddine and Wehbe, 2018). However, many countries like the UAE, Thailand, Singapore and Australia have reported failures in the implementation of LC on account of several factors including lack of awareness and knowledge about the concept of LC, lack of resources, lack of selection criteria, lack of improved sustainability and internal management resistance (Moyo and Chigara, 2021; Puram et al., 2021; AlBalkhy and Sweis, 2022; Xing et al., 2021).

In a developing country such as India that is vulnerable on account of various issues, the two most prominent ones being increasing population and political tensions, the construction industry is a crucial sector to help alleviate the problems to some extent. The construction sector of India is the third largest contributor to gross domestic product (GDP) in India with 7.16% of the total GDP (Sector-wise GDP of India, 2022). However, the construction sector of India falls behind in terms of sustainable development due to many reasons, some of the critical ones being cost overrun, safety-related issues, poor productivity and performance, unskilled workforce, distorted and unhygienic working conditions, delays and reworks (Sadeghi et al., 2022; Windapo et al., 2021; Dixit, 2021). In light of the aforementioned issues, there is an urgent need to rethink the management of construction projects in India that can help in overcoming the issues with construction management in India. According to Dr Koshy Varghese, Professor, Building Technology and Construction Management Division, Department of Civil Engineering, Indian Institute of Technology (IIT) Madras, Indian businesses are aware of the need to increase production by reducing waste. Leading businesses have started working toward lean. However, because of the industry’s fragmentation, it will take some time for all participants to align their operations with the lean-based methodology (Construction world, 2022). Construction is not an fast-moving consumer goods product, which is something companies cutting costs in the near term need to recognize. It endures for decades or perhaps millennia. As a result, serious players should consider LC as an investment and a means of setting themselves apart from the competition. Lean is an expense, not a cost. The building sector in India uses a lot of labor. Dealing with machines requires far more formality than doing business with people. The majority of the identified obstacles include variable temporary multiorganization execution teams for each project; constant inflow of unskilled labor and outflow of trained labor from different labor contractors; subcontractors’ perception of their workforce; and lack of collaborative information sourcing teams (design consultants and project management consultancy) causing a delay in the timely availability of desired changes and approvals (Jagannathan et al., 2022). One of the most well-known LC technologies that provide a solution to the issues with production management on building sites is The Last Planner System® (LPS). Construction firms throughout the world have reportedly used Last Planner since its launch approximately 20 years ago with claimed success. Even though the Last Planner was initially intended to alleviate some of the critical path method’s drawbacks, task continuity was not specifically addressed. Additionally, the LPS does not provide any explicit visual aids other than production planning and control and reasons for noncompletion charts (Dave et al., 2015). The major objective of the paper by Barbosa et al., 2013 is to illustrate, step-by-step, the whole implementation process of several LC principles, tools and techniques while also discussing the advantages realized in just one year. The construction business had no prior experience with lean ideas and spent a year receiving expert counsel and attending regular courses on the subject. The engineers began the implementation process during the study with the design of the production system and continued with the production planning and control using the LPS. A project management system written in the Delphi programming language was also created. It contains long, medium and short-term plans as well as details on staff availability and productivity control, safety, quality and apartment customization (Barbosa et al., 2013). The purpose of the article authored by Mano and coauthors was to identify the most significant hurdles to effective LC adoption in the civil construction sector. The study revealed that despite the research providing several challenges to LC, organizations may find it challenging to identify the presence of these barriers. The objective of this research was to simplify the knowledge of the challenges by identifying a limited collection of criteria that are crucial to effective LC implementation. The study was carried out in Brazil using a questionnaire-based survey with 135 responses from civil construction professionals (Mano et al., 2023).

The paper is divided into six sections. Section 2 explains the literature review on the lean concept and barriers to LC. Section 3 illustrates the research methodology adopted for carrying out the analysis. Section 4 presents the data analysis and results of the study, followed by a discussion and findings with theoretical and managerial implications in Section 5. Section 6 outlines the conclusions with limitations and scope of the future opportunities.

2. Literature review

3. Research methodology

This research work aims to present an overarching analysis of LC implementation in the construction sector of India. To determine the biggest obstacles to the adoption of LC in the Indian construction sector, this study uses an analytic hierarchy process (AHP) that combines qualitative and quantitative methods. It is hoped that by serving as a framework for comparison, this study will help to effectively change how construction projects are managed in India.

Broadly the process of gathering, validating and finalizing the set of challenges in the adoption of a lean framework can be divided into three stages.

In the first stage, based on the extant literature review on the challenges in the adoption of the lean principle in various organizations, we proposed an initial list of major challenges in construction organizations. The list was presented to research scholars and academicians active in the field of lean principles and related academic work; and construction organizations’ personnel who agreed to provide suggestions on the appropriateness of the set of challenges gathered in the first stage.

Certain challenges were removed from the list upon the suggestions of the participants, who pointed out that some of those challenges were redundant and irrelevant to the construction industry. We included some new challenges which highlighted the industry-specific issue of the adoption of the lean principle in construction organizations. The updated list from the first stage was circulated to a group of a few intended respondents, including researchers, academicians and construction management personnel for pilot testing that marked the second stage.

There were certain discrepancies in the form of wording and ambiguity in the meaning of some challenges that were addressed in this stage. In the final stage, the list was finalized and circulated to the experts for gathering their responses on the severity associated with the challenges, which were subsequently analyzed using a multicriteria decision-making method based on the AHP, the details of which can be found in the section that follows.

The details of the experts considered for this survey are presented in Table 3.

The flowchart of the proposed research work is presented in Figure 2.

The AHP method is used as a general judging strategy as well as a qualitative technique for dealing with difficult and unstructured issues (Saaty, 1988). AHP is helped to break down a complex issue into several intermediate levels of the hierarchy (Crowe et al., 1998; Saaty, 1980; Kumar et al., 2022b; Verma et al., 2021). The assessments of experts and academicians establish the order of importance for each of the contributing variables. Pair-wise evaluation findings based on professional judgment and expert panel have been related to pairs of homogeneous criteria (Saaty, 1980; Kumar et al., 2022b; Verma et al., 2021). The AHP method is frequently used for a variety of objectives in various contexts.

The different steps concerned in the AHP technique are as follows.

Step-1: Define the objective of the study/Construct a decision situation into the objective.

Step-2: Develop an AHP hierarchical framework.

Step-3: Compilation of empirical information through the combined judgment of professionals.

Step-4: Establish pair-wise comparisons (to evaluate priority weights of components) by using Saaty’s 1–9 point scale.

Step-5: Normalize the column of numbers by dividing each entry by the sum of all entries in the column:

The approximate priority weight (W1, W2,…….Wj) for each factor is obtained as:

Here, n is the number of components; a is the cell value assigned in a pairwise matrix.

Step-6: Examine the consistency of obtained pair of norms.

Here, CI is the consistency index; λ_max is the maximum value of eigenvalues and n is the number of components.

Step-7: Calculate the consistency ratio (CR):

4. Data analysis and results

The most significant obstacles to the adoption of LC in India’s construction industry have been determined using the AHP technique. As illustrated in Figure 1, a hierarchy between the conscientious barriers has been constructed with the aid of professional judgments to achieve this goal. The hierarchy structure has three levels, as shown in Figure 1, with Level 1 representing the primary goal of the study, Level 2 representing the major categories of barriers and Level 3 representing subcategories.

On a scale from “1” to “9,” the degree of preference was assigned to pairwise comparisons of key obstacles (Saaty, 1988) as stated in Table 2, where “1” denotes equal importance and “9” denotes extreme or absolute importance. Table 3 shows the summary of demographic details.

A pair wise comparison method (PWCM) is generated for each of the subcategory barriers and the main-category accountable obstacles by the hierarchy structure and the collective professional judgment. Table 4 displays the pair-wise comparison scale, and Table 5 shows the PWCM for main-category barriers.

The normalized and priority weights of the major category obstacles are shown in Table 6; managerial (M) is the category with the highest level of influence, with a priority weight of “0.361” chased by inadequate resources (IR) with a priority weight of “0.309,” improper planning (IP) with a priority weight of “0.126,” labor (L) with a priority weight of “0.117,” IK with a priority weight of “0.053” and JIT with a priority weight of “0.034,” respectively.

Further, relative weights (δ) are calculated by using the formula: A × W_j = δ

A = pair-wise comparison matrix; where j = 1, 2,…n

The eigenvector “λ”:

Eigenvalue maximum, λ_max = 6.542, CI = 0.108 and CR = 0.964. Similarly, Tables 7 to 12 show the pair-wise comparison matrix for subcategory barriers.

Tables 13 to 18 show the normalized and subcategory barriers’ priority weights. The relative relevance of barriers in the management category and their priority weights is as: lack of client focus and poor comprehension of customer needs (M1) appeared as the most essential barrier with a priority weight of “0.259.” Poor management and lack of leadership abilities (M2) is the second highest significant barrier, with a priority weight of “0.202.” Change management resistance (M3) has a priority weight of “0.170,” which is the third main barrier. Lack of leadership for quality (M4) is the 4th most significant barrier receiving “0.121” as priority weight. Lack of stakeholder interaction and transparency (M6) has a priority weight of “0.089,” which is the fifth main barrier. Lack of backing and dedication from high management (M5) is the sixth positioned barrier with a priority weight of “0.081.” Inadequate lean awareness and comprehension (M7) is the second last barrier, with a priority weight of “0.040.” Inadequate trash identification and management (M8) is the last positioned barrier under the managerial category, with a priority weight of “0.037.”

Under the IK category, the barrier project participants’ unwillingness to share risks (IK5) is a challenging barrier to resolve with a priority weight of “0.348.” The results are not fast and often only partially visible and may not conform to high (IK1) is the second most important barrier with the priority weight of “0.231.” Results are not immediate, frequently only partially evident and may not meet high expectations of management (IK2); the priority weight of “0.159” is the third most important barrier. Lean may result in increased costs or implementation costs (IK3) is the 4th most significant barrier receiving “0.114” as priority weight.

Poor professional pay, a lack of incentives and a lack of desire (IK6) have a priority weight of “0.065,” which is the fifth main barrier. Inaccurate and incomplete designs, as well as a failure to apply the design principle constructability (IK4), the sixth positioned barrier with a priority weight of “0.053.” Insufficient dissemination of the knowledge required to start a learning cycle and take remedial action (IK7) is the last barrier with a priority weight of “0.030.”

Under the IP category, the barrier absence of long-term thinking and planning (IP1) is a significant and top-positioned barrier with a priority weight of “0.409.” Avoid delegating decision-making and responsibility to people outside of top management by centralizing decision-making (IP5) is the second most important barrier with a priority weight of “0.267.” Organizational structures that are hierarchical or inappropriate (IP4) have a priority weight “of 0.160,” which is the third most important barrier. Lack of quality planning (IP3) is the 4th most significant barrier receiving “0.114” as priority weight. Lack of a long-term philosophy and planning (IP2) has a priority weight of “0.050” and is the fifth main barrier.

The ranking of subbarriers under the Labor (L) category as additional labor cost (L5) is the most crucial barrier attaining the highest priority weight of “0.357.” Labor views lean as too complex (L4) as the second most crucial subbarrier with a priority weight of “0.258.” Moreover, lack of training for employees (L3) and employee reluctance to change and anxiety about unfamiliar procedures (L1) hold third and fourth positions within the Labor (L) category with a priority weight of “0.178” and “0.142,” respectively. The fifth and sixth position barrier under this category is unskilled labor and the site foreman’s low level of education (L2) and high employee turnover (L6), which received priority weights of 0.041 and 0.024, respectively.

Under the IR category, the ranking of the subbarrier is as strict procurement requirements and approval (IR5) is the most important barrier by attaining the highest priority weight of “0.357.” Limited use of design-build procurement (IR4) is the second most important subbarrier with a priority weight of “0.243.” Moreover, poor delivery performance and late delivery of materials (IR1), and lack of enduring connections with suppliers (IR2) hold third and the fourth position within this category with a priority weight of “0.173” and “0.128,” respectively. The fifth and sixth position barrier under this category is “only occasionally using off-site construction methods and not prefabricating (IR3)” and lack of government support (IR6) which received priority weights of 0.063 and 0.036, respectively.

The priority weights and relative importance of barriers under the managerial category are as: uncertainty in the supply chain (JIT1) appeared as the most essential barrier with a priority weight of “0.548.” The high inflation rate (JIT2) is the second highest significant barrier with a priority weight of “0.317.” Poor infrastructure in transportation and communications (JIT3) has a priority weight of “0.081” and is the third main barrier. Discounts of prices of a large number of materials (JIT4), which are the 4th most significant barrier receiving “0.054” as priority weight.

Additionally, global weights are determined by dividing the subcategory barrier priority weights by the corresponding main category priority weights. For instance, the priority weight for the category that is management (M) oriented is 0.703, while the priority weight for the subcategory that has no barrier to top-management commitment is 0.657. As a result, this barrier’s overall weight is 0.703*0.657, which is 0.462. Similar to this, Table 19 displays the overall weights and rankings of all subcategory barriers. The weights of the main category barriers are shown in Figure 3, and the weights of subcategory barriers are shown in Figures 4 to 9, respectively. The global weights of all subcategory barriers are shown in Figure 10.

5. Discussion

Understanding and planning for potential roadblocks to the systematic application of LC techniques in construction projects are crucial for integrating lean practices into the construction industry. The analysis revealed that the major obstacle to the implementation of LC in the construction sector is “Strict procurement requirements and approval (IR5)” under the IR category. The lengthy and time-consuming process of acquiring approval from the higher authorities and stringent procurement processes is the major impediment to the process of implementing LC practices in the construction sector of India.

“Lack of client focus and poor comprehension of customer needs (M1)” has acquired the second rank in the overall ranking of barriers to LC implementation in the construction sector. In the construction sector of India, little attention is paid to the details of the requirements of the clients and customers when the decision has to be made regarding the adoption of new technologies or frameworks in supply chains. More focus is placed on the deadlines and completion of the projects. This leads to a state of oblivion concerning the advantages lean practices have the potential to offer. This finding is aligned with Dey et al. (2022) where the study looked at how the several stages of a closed-loop supply chain, such as design, procurement, production, distribution, consumption and recovery, may be used as fundamental factors for adopting circular economy principles. According to the study, evaluating the existing state of closed-loop supply chain functions for small- and medium-sized firms (SMEs) in four different nations can assist in identifying the obstacles they encounter when implementing circular economy practices and determining solutions to improve. While the principles of reducing waste, reusing resources and recycling are integrated into the closed-loop supply chain’s design, production and distribution stages in Greece to achieve better economic, environmental and social performance, the procurement stage has a negative impact and the consumption and recovery stages do not contribute to this. This is due to a lack of support from SME suppliers and consumers, as well as a lack of enthusiasm inside SMEs. It was suggested that the government may help to create a favorable climate for the adoption of circular economy practices by providing appropriate support, such as financial aid and programs such as training, certification and laws. As a result, there are several opportunities to improve the procurement, consumption and recovery functions of Greece’s closed-loop supply chain.

“Limited use of design-build procurement (IR4),” “Poor management and lack of leadership abilities (M2)” and “Change management resistance (M3)” are the third, fourth and fifth most influential barriers in the implementation of LC. Senior management and decision-makers in responsible positions in the construction sector are negligent and apprehensive to incorporate new methods and technologies of operations and thus deprive the industry of the numerous benefits offered by following LC practices. This situation is also fueled by the employees and workforce when there is a certain tendency to not accept change in the operations and supply chain activities. Coupled with the points mentioned above, the lack of efficient leadership poses a major obstacle to the implementation of LC practices in the construction sector. This finding is also supported by the observations made by Maware and Parsley (2022), which emphasized that the most difficult aspect of implementing lean is creating a sustainable culture, which is followed by a systems approach to cultural transformation by leadership and a lack of a strategic transformation strategy. Additional difficulties include a lack of organizational commitment, weak problem-solving abilities, a lack of key performance indicators, employee reluctance to change, role limits and insufficient data gathering. Manufacturing businesses also have challenges in terms of sharing success, standardizing processes, removing nonvalue-added activities, developing a management succession plan and gaining management support.

“Absence of long-term thinking and planning (IP1)” under the category of inappropriate planning (IP) acquires the next place in the list of barriers to LC implementation. Implementing a new method of operating business requires meticulous and comprehensive planning, without which it is difficult and, on some occasions, almost impossible to sustain the new framework and reap benefits from it. The construction sector is highly fragmented in structure, due to which various departments within the construction organizations fail to collaborate and thus resulting in disorientation and ambiguity in the dissemination of important information. This further results in distortions in understanding the principles of lean management in its entirety, thereby resulting in disregarding the implementation of LC in construction organizations. In a similar study conducted by Huaman-Orosco and Erazo-Rondinel (2021) to study the major challenges in the implementation of LC in Peru, it was found that a lack of clear understanding and scope coupled with a lack of planning and thinking affected the implementation of a large extent. According to the information gathered from implementers and the literature reviews used in the study, the main barriers identified were: “lack of government policies,” “lack of collaborative work between academia and business,” “high cost of implementation” and “lack of knowledge of lean in university graduates.” The challenges highlighted in worldwide research literature reviews are not represented in Peru; hence, individual barriers vary based on geographical area, political situation and industry type. Peruvian professionals have a poor degree of lean awareness and understanding. These findings highlight the need of emphasizing philosophy and technology.

“Additional labor cost (L5)” and “Lack of enduring connections with suppliers (IR2)” under the categories of labor and IR are placed next in the list of barriers to the implementation of LC in the construction sector. It is imagined that the inclusion of LC practices might involve additional training of the workers and employees, which is the cause of extra cost to be incurred by organizations. This is true to some extent, especially in the context of the Indian construction industry were to embrace LC practices in the supply chain and operations activities, dedicated and comprehensive training will be required to educate the workforce on the need for lean management practices, and thereafter ensure that proper protocols are followed while working on lean principles. Until the time organizations have transparent and collaborative relationships with the suppliers, the idea of having a full-scale LC framework is hard to put to work. If suppliers do not adhere to the LC principles, then the organizations receiving raw materials and other supplies from them cannot be considered lean in any aspect. Thus, the lack of enduring relationships with the suppliers is a crucial impediment on the path of full-scale LC principles implementation in the construction sector of developing nations such as India. The obstacles like labor costs and lack of enduring relationships with suppliers were also revealed as the challenges in the LC implementation in Zimbabwe, Ethiopian and Jordanian organizations in the studies conducted by Moyo and Chigara (2021) and Al Balkhy et al. (2021), respectively. Moyo and Chigara (2021) revealed that the most significant impediments to implementing LC were integration, performance, human capital management and quality management constraints. There were no significant variations in perception depending on gender, job title or degree of education when all barriers were evaluated combined, indicating universal agreement on the hurdles. When individual hurdles were explored, it was shown that architects and individuals with certificates or degrees lacked the necessary managerial abilities for LC implementation. A questionnaire with 30 barriers was used in Jordanian research by Al Balkhy et al. (2021) to identify impediments to adopting LC concepts in the construction sector. A total of 326 questionnaires were completed by contractors, consultants and owners. The challenges were first classified into three categories, but factor analysis separated them into two: internal environment-related and noninternal environment-related, which comprised labor, material and organizational structure challenges. Owners and consultants in Jordan’s construction sector regarded “lack of support and commitment from senior management” as the most important hurdle to implementing lean concepts, while contractors ranked it third. Numerous studies have found that senior management support is critical for the effective implementation of lean methods. This view may be influenced by the prevalence of top-down management in Jordanian construction, as well as the frequency of family-run businesses where the owner lacks business administration knowledge.

“Avoid delegating decision-making and responsibility to people outside of top management by centralizing decision-making (IP5),” “Lack of stakeholder interaction and transparency (M6),” “Labour views lean as too complex (L4)” and “Lack of backing and dedication from high management (M5)” are the barriers ranked 11th, 12th, 13th and 14th in the overall ranking. In construction organizations, the decision-making and making of the final call are mostly confined to the top management. This limits the organizations to benefit from the diversified views of workers in different levels and departments. Lack of acceptance of different perspectives on important issues, such as the incorporation of LC management practices in organizations, results in the non-adoption or implementation of newer and potentially better ways of operations in supply chains. The role of management is extremely critical in the possibility of implementing new technology or a new framework of operations in any organization. When the stakeholders are not consulted in the major decisions about the betterment of organizations, then this lack of transparency will result in biased judgments with a lot of room for incorrect and inappropriate decisions that can hamper the reputation and productivity of organizations. The higher management must take into account the fact that it is their responsibility to ensure the workers are properly educated and made aware of the benefits provided by adopting LC practices at the organizational level as well as the individual level. The crucial role played by the top management in influencing the decision and finally implementing new technology and framework in supply chains was also highlighted by Al Balkhy et al. (2021), Shaqour (2022) and Nwaki et al. (2021). Shaqour (2022) suggested that the Egyptian construction industry confronts managerial issues and is seen as a waste-generating business that harms the economy and the environment. Implementing LC methods is regarded as critical to enhancing performance and lowering waste. Data was gathered from 162 experienced building experts in Egypt’s future capital city. The results demonstrated that using lean tools in construction increases time, cost, quality, safety, the environment and relationships, as well as the value of resources and money. Nevertheless, respondents’ awareness of lean ideas was lower than their degree of adoption, and the main advantages of lean adoption were economic. The primary advantages of implementing lean tools were increased process control, planning, material storage control and time savings.

“Lack of training for employees (L3)” and “Organizational structures that are hierarchical or inappropriate (IP4)” account for the barriers to the implementation of LC practices in construction organizations owing to the lack of dedicated initiatives by the senior management construction organizations in providing formal training to the employees regarding the implementation of LC practices. Since the organizational levels are hierarchical in structure, there is a lack of information sharing and coordination between members at different levels of the corporate hierarchy. This leads to distorted and unequally distributed information flow, thereby accentuating the disharmony in the overall arrangement of the availability of correct and timely information among all the stakeholders.

“Only occasionally using off-site construction methods and not prefabricating (IR3),” “Uncertainty in the supply chain (JIT1),” “Project participants' unwillingness to share risks (IK5),” “Employee reluctance to change and anxiety about unfamiliar procedures (L1)” and “Inadequate lean awareness and comprehension (M7)” are some of the barriers that indicate the importance of the involvement of senior management in the implementation of new technology or a new framework of operations such as LC in supply chains. Most of the construction projects undertaken in the Indian landscape involve on-site activities, thus limiting the possibility of using off-site construction methods. LC is, therefore, not as easy to implement as it will require a complete shift from the mode of operation from on-site to off-site construction with seemingly uncertain outcomes. Employees’ resistance to change is a major hurdle in the process of embracing new technology. This requires a thorough investigation into the issues of the workforce and an understanding of the inhibitions that impede the acceptance of LC practices in supply chain management. This problem was also highlighted in the study conducted by Lohne et al. (2022) in the Norwegian AEC industry. Using a narrative-based qualitative method, this research examines the inception and effect of LC on the Norwegian AEC sector. The paradigm shift idea and empirical knowledge in the form of narratives are employed. The implementation of LC ideas and technologies in Norway has been reliant on promoters, and the involvement of active promoters like Dr Glenn Ballard is regarded as critical to its success. Cultural characteristics of the Norwegian AEC sector, such as a high level of trust and bottom-up organizations with low layers of hierarchy, are highlighted as critical success factors. These important features might be applied in various situations.

“Lack of quality planning (IP3),” “Inadequate trash identification and management (M8),” “Results are not immediate, frequently only partially evident, and may not meet high expectations (IK1),” “Lack of government support (IR6),” “High inflation rates (JIT2)” and “Results are not immediate, frequently only partially evident, and may not meet high expectations of management (IK2)” are some of the barriers that are placed in a relatively lower position vis-à-vis other higher ranked barriers. Nonetheless, these barriers require equal and careful attention to assess the role played by them in the implementation of LC practices in construction supply chains. Construction sites are very unpredictable in comparison to the steady conditions in factories, where only the material moving through the workstations in factories needs to be planned and monitored. As the project advances, construction teams must manage not only the flow of supplies but also the spatial flow of their workstations, adding complexity. Implementing visual control and layout planning strategies is challenging due to the workplace’s constant change. It is extremely challenging to conduct benchmarking and improvement efforts in decentralized production. On building sites and during preconstruction, there is an unmanageable amount of waste due to all of these causes of variation. The goal of LC principles is to assist teams in locating and removing sources of variation to lessen any unfavorable effects (Prayuda et al., 2021). Traditionally, construction management techniques have focused on streamlining tasks at the individual level, such as attempting to cut down on the number of times roofers need to install a new roof. On the other hand, concentrating simply on enhancing particular processes may not benefit the system as a whole and may even unintentionally increase waste. The fact is that the great majority of waste produced by any organizational system occurs during handoffs between tasks or steps in the process. Lean challenges all stakeholders to develop and implement better methods of managing the entire construction process, from beginning to end, as construction crews can only optimize their operations for quicker, more reliable delivery through a holistic understanding of how materials and information flow through the process. Financial issues were hindered by inflation brought on by unstable construction market conditions, higher building costs and low professional salaries (Olatunji, 2008). The absence of rewards or incentive programs in a building project was another factor contributing to the barriers to LC's widespread deployment. To ensure that the building project is completed successfully, sufficient finance sources are required. By including a contingency cost, you may protect your construction project against price increases caused by unstable construction markets.

6. Conclusions, limitations and scope of future opportunities

LC is developing and proving to be beneficial in many locations throughout the world, so it is important to research the obstacles that its adoption encounters, particularly in nations where this philosophy is not widely known or formally applied. This study takes India as a case to examine the most significant impediments using the perspectives of several industry participants, including construction managers, academicians and research scholars. The results revealed the most significant barriers to adopting lean in the Indian construction sector belong to the categories “Management” followed by “Inadequate resources,” “Inappropriate planning,” “labor,” “Inadequate knowledge” and “Just in time.” The major obstacles listed under each of the categories include “Strict procurement requirements and approval,” “Lack of client focus and poor comprehension of customer needs,” “Limited use of design-build procurement,” “Poor management and lack of leadership abilities,” “Change management resistance,” “Poor delivery performance and late delivery of materials,” “Absence of long-term thinking and planning,” “Lack of leadership for quality,” “Additional labour cost,” “Lack of enduring connections with suppliers,” “Avoid delegating decision-making and responsibility to people outside of top management by centralizing decision-making,” “Lack of stakeholder interaction and transparency,” “Labour views lean as too complex,” “Lack of backing and dedication from high management,” “Lack of training for employees,” “Organizational structures that are hierarchical or inappropriate,” “Only occasionally using off-site construction methods and not prefabricating,” “Uncertainty in supply chain,” “Project participants’ unwillingness to share risks” and “Employee reluctance to change and anxiety about unfamiliar procedures.”

Therefore, the following techniques might be suggested to increase the adoption of LC in India: first and foremost, the management of construction firms must take the initiative in the transition and adopt new methods that can improve the performance and efficacy of the sector. Second, the Indian Government, universities and organizations should assist in the spread of knowledge regarding lean building. More studies may be published, new training facilities or programs may be built and new formal education workshops and university programs may be created to achieve this. Thirdly, management should offer training programs to encourage the participation and inventiveness of workers at all levels.

The study’s major drawback is that it looked at LC adoption generally. The limitations of the current study were not examined concerning any particular lean tool or technique (e.g. LPS or BIM). Future research is therefore required to examine the use of and obstacles to one or more particular tools. Also, future studies can examine the factors influencing lean adoption by including more participants from diverse areas to fully express the underlying causes of the issues. The study used purposive sampling for the selection of respondents. Purposive sampling, however, can have a variety of disadvantages. Purposive sampling can be biased, much like other nonprobability sampling strategies. Results have a high risk of bias because the selection of the sample units relies on the researcher’s subjective judgment.

The study can be used by construction organizations as a reference framework to assess the adoption of LC, to learn more about the elements required for implementation or to research the difficulties encountered throughout implementation. Therefore, these businesses can create plans that will enhance the acceptance and use of lean ideology.