Modelling the interrelationship between factors for adoption of sustainable lean manufacturing: a business case from the Indian automobile industry

ABSTRACT

Growth of automobile industry plays a significant role in the Indian Economy. Global warming and increased pollution levels force all countries to revisit their environmental policies towards achieving sustainability. In this view, the automobile industry is under tremendous pressure from both customers and government for sustainable development. Therefore, Indian automobile industry focuses on business improvement through profitability enhancement as well as environmental development through sustainable lean manufacturing. Critical success factors (CSFs) for sustainable lean manufacturing are identified from existing literature, and experts’ guidance has been considered to carry out the inter-relationship between CSFs in sustainable lean manufacturing implementation using Interpretive Structural Modelling (ISM) methodology. Top management identified as the influential CSFs, which help in implementation of SLM and leading other CSFs. Driving and dependent factors are also summarized in an Indian automobile industry perspective. The result of research based on data collection from small-, medium- and large-scale automobile sectors. It has been analysed earlier that sustainable manufacturing (lean and green practices) delivers superior results. Hence, the automobile industry needs to adopt sustainable lean manufacturing for achieving economy, social and environmental growth. lean manufacturing. Critical success factors (CSFs) for sustainable lean manufacturing are identified from existing literature, and experts’ guidance has been considered to carry out the inter-relationship between CSFs in sustainable lean manufacturing implementation using Interpretive Structural Modelling (ISM) methodology. Top management identified as the influential CSFs, which help in implementation of SLM and leading other CSFs. Driving and dependent factors are also summarized in an Indian automobile industry perspective. The result of research based on data collection from small-, medium- and large-scale automobile sectors. It has been analysed earlier that sustainable manufacturing (lean and green practices) delivers superior results. Hence, the automobile industry needs to adopt sustainable lean manufacturing for achieving economy, social and environmental growth.

KEYWORDS:

• Sustainable lean manufacturing
• critical success factors
• interpretive structural modelling
• Indian automobile industry

1. Introduction

Supply chain management (SCM) plays a vital role in implementing sustainable manufacturing and to improve organisation performance (Shi, Wu, and Tseng 2017; Wu et al. 2016) in relation to the dynamic growth and development encouraged by the automobile industry particularly the small- and medium-sized enterprises (SMEs). SMEs are having more than 90% market share of the total automobile industry and exploring 6% employment, arguably the strongest part of economies worldwide IEA (2015). In India, the automobile industry has maximum share in the overall nation’s growth rate. Reportedly, 7.1% growth has been calculated in total country’s Gross domestic product (ET Auto Report). The automobile industry in India is the world’s 4th largest manufacturer of cars and 7th largest manufacturer of commercial vehicles in 2018. Two-wheeler segments are leading with 80% market share in the Indian automobile market by having a focus on young population. Passenger vehicle segment and commercial vehicle segment are having growth rate of around 16.2% and 4.99%, respectively, over the last financial year. Government initiatives are playing a major role in the growth of automobile leaders and expected to make India a leader in the 2 W and 4 W market by 2020 (Media Reports like Society of Indian automobile manufacturer (SIAM), Confederation of Indian industries (CII), etc.). The report shows the significant contribution of the automobile industry in the Indian economic growth.

The government now focuses towards becoming a global manufacturing as well as a research and development (R&D) hub. National Automotive Testing and R&D Infrastructure Project (NATRIP) centres as well as a National Automotive Board are involved in facilitating between the government and the industry (Government of India, 2015). Now, huge opportunities are available to explore in research and development activities. Automobile supply chain partners are affected by limited resources like human and financial condition. Rise in middle class population and their income has led to a more than ever high rate of demand, and the Indian automotive industry is expected to increase exports of vehicles by five times over the next few years (Automotive mission plan: 2016–26). Due to the significant cost advantages, automobile firms can save up to 25% cost on operations when compared to Europe and Latin America. However, India will face significant questions about rapid urbanisation, resource scarcity, and high levels of poverty in the coming years (Anil et al. 2014). In the past few decades, India has undergone major transitions from being an agrarian society to an industrial society and accordingly the consumption of both renewable and non-renewable resources has increased. Extraction of primary raw materials has increased by around 420% between 1970 and 2010. According to United Nations Environment (UNE), India consumed about 42% and are renewable biomass and 38% are non-metal minerals. The conventional make-use-dispose model with increasing population has led to the demand-supply gap more than ever against the ability of the planet to replenish the resources.

The Federation of Indian Chambers of Commerce and Industry (FICCI) in collaboration with experts from EU identified potential areas to build partnerships for resource efficiency models in India. The nation spends around 120 billion US dollars each year on importing crude oil and the nation’s dependency on this source of petroleum has increased 8% over the last decade. India’s plastic consumption is expected to grow to 20 mn tons by 2020 and about 40% of the plastic wastes eventually end in landfills. According to the National Steel Policy 2017, India is estimated to consume 160 kg per capita by the end of 2030. However, iron ore production lags behind the demand, and iron ore reserves are expected to exhaust by the next 10 years makes India a net importer of iron ore. Similarly, the demand for copper is growing at a rate of 7% till 2030, and India just contributes to only 2–3% of the world’s reserves for copper . Indian consumers account for around 650 tons of gold in 2017 whilst the domestic production only met 0.2% of the total demand constituting an import bill of 35 billion US dollars (FICCI, 2018). Thus, it can be summarised that India is experiencing severe environmental degradation due to the economy struggles of supply meeting the demand.

Implementation of sustainable lean manufacturing environment helps in dealing with present situation of scarcity in resources by promoting human efforts, space optimisation; reduction in total lead time and number of defects (Womack, Jones, and Roos 1990; Kumar et al. 2016). Small- and medium-scale enterprises hold around 13% of global energy consumption yearly IEA (2015). The usages of natural resources are increasing year-by-year, and IEA pointed out the drastic increase from 82.5 million tons to 150.5 million tons in 2015 in India IEA (2015). The Government of India had identified the problem much earlier and promoted a ‘National Action Plan on Climate Change’ in June 2008 with a target to reduce carbon intensity by 20–25% by 2020 (The Government of India, 2008). So it is needed for Industries to engage Sustainable Manufacturing (SM) in response to environmental challenges like exhaustion of natural resources, pollution and global warming. SM involves a set of activities to minimise waste and provide a sustainable environment (Ghazilla et al. 2015; Mittal and Sangwan 2014a; Singh, Singh, and Dhingra 2012; Luken and Van Rompaey 2008; Perez‐Sanchez, Barton, and Bower 2003).

The concept of lean generally focuses on gaining greater production revenues by lowering material and labour costs. Lean manufacturing has been a set of continuous improvement activities related to the Toyota Production System (TPS) and Just-In-Time Manufacturing systems. Lean is the elimination of waste everywhere while adding value for customers. On the other hand, sustainability is oriented towards balancing the three pillars: economic, environmental and social – also known informally as profits, planet and people. The concept of sustainability can be seamlessly integrated with Lean Manufacturing practices to optimise production activities and processes towards improved environmental, worker health, safety and energy performance (RocíoRuiz-Benítez and Juan, 2018). These two concepts are not only more overlapping, which we discuss in the forth coming section, but also mutually support each other. Hence, we propose a Sustainable-Lean manufacturing approach for a better future.

Factory size also plays a major in planning the strategy for sustainable lean implementation as both large-scale and small-scale industries have different operational targets (Shah and Ward 2003; Wu et al. 2016). The ‘Make in India’ initiative has forced many foreign large-scale industries towards their expansions in India and led ways towards low-cost material from Indian manufacturing market OECD (2013). Also, to align automotive sector and growth supply chain, partners (Tier 1 and Tier 2 suppliers) need to adopt sustainable lean manufacturing techniques to come forward and compete with large manufacturers (Thanki, Govindan, and Thakkar 2016).

Many researchers have explained the possibility of sustainable manufacturing through improvement in economy, social and environmental performance (Thanki and Thakkar 2016; Verrier et al. 2014; Diaz-Elsayed et al. 2013). Galeazzo, Furlan, and Vinelli (2014) have concluded with improved results of lean and green integration (Bergmiller and McCright 2009b; King and Lenox 2001); while other studies explained about the positive linkage between lean and green manufacturing (Dües, Tan, and Lim 2013; Hajmohammad et al. 2013). Researchers explained the combination of lean and green manufacturing could be treated as a positive step towards sustainable improvement in the organisation (EPA 2007; Bergmiller and McCright 2009b). According to Verrier et al. (2014), a defined path of lean and green manufacturing system has to be given for successful adoption and derive the required result. According to Govindan, Diabat, and Shankar (2015), the effectiveness of implementation is different from one nation to other nation as region, culture, economy and policy conditions also change. It gives thought to industrialist to think of specific sustainable manufacturing strategies for implementation. There are many factors, which have been identified and used by many consultants in industries in getting results.

Sustainable systems strengthen with the help of lean manufacturing to eliminate waste from industries (Heilala et al. 2008). In addition to the same, this study offers to consider the critical success factors (CSFs) theory and analyse the success factors for sustainable lean manufacturing implementation. Initially based on extensive literature review and interview with relevant industrial experts, 20 factors for sustainable lean manufacturing implementation are identified and our research questions are framed as below:

RQ1: What are the CSFs for sustainable lean manufacturing implementation in the Indian automobile industry?

RQ2: What are the impact of CSFs on the economy, society and environment?

RQ3: What are the inter-relationships between identified CSFs?

Based on the research questions, objectives of research are formulated in four phases such as:-

(1) To identify the CSFs for implementing SLM from existing literature.

(2) Study the impact of CSF on the economy, society and environment based on industrial experts.

(3)To develop the ISM-based model to understand the inter-relationship between various CSFs. (4) To identify the driving and dependent CSFs using MICMAC analysis.

The remaining of this research paper is formulated as follows: Section 2 provides the review background of sustainable lean manufacturing in detail. Section 3 describes the problem in environment description. Section 4 illustrates the research approach of Interpretive Structural Modelling (ISM) technique steps and importance for this study. Also, this section covered questionnaire development and data collection. Section 5 discusses the formation of ISM model for this study, and Section 6 details the MIC-MAC analysis. Sections 7 & 8 are dedicated towards providing critical discussions of present study results and its conclusions, respectively.

2. Review background

In this section, the context of lean and sustainable manufacturing processes are explained in the manufacturing sector point of view with the help of earlier literature. CSFs have also been discussed for sustainable lean manufacturing implementation in automobile industry. To ensure an improved understanding of the theory behind this research, literature review is organised into three different sub sections. The first two sections provide overviews of the lean manufacturing and sustainable manufacturing individually and detail their need in the Indian automobile industry context. The third sub section aims at addressing the earlier efforts in Sustainable-Lean literature and also reveals the gaps in the existing, attempts and presents the highlights of this research.

2.1. Lean manufacturing in India

Lean manufacturing reduces all types of wastes from production system, which shows the path towards improvement in lead time and quality of the product (Thomas et al. 2012). The goal of Lean Manufacturing is ‘to get the right things to the right place at the right time, the first time, while minimizing waste and being open to change’. Following lean manufacturing principles help companies to deliver products on demand efficiently with minimum inventory, maximised use of available skill sets, while focusing on resources conservation (Bhasin and Burcher, 2006). Lean manufacturing not only facilitates the organisation to achieve excellent business performance by reducing manufacturing lead time and cost but also improves product quality and delivery time, which eventually improves customer satisfaction and provides a competitive edge. According to Singh, Garg, and Sharma (2010) industries in India still progressing very slow to implement lean manufacturing. Some barriers like less working capital; poor technology; poor management skills and lack of training reduce the speed of lean implementation (Upadhye, Deshmukh, and Garg 2010). According to Eswaramoorthi et al. (2011), there is an aggressive approach to implement lean manufacturing and improve current status of lean practices adoption. Panizzolo et al. (2012) also stated lean manufacturing in industries in medium to low range due to lack of lean expertise and low financial resources (Ghosh 2012). Kumar et al. (2016) focus on factors affecting lean implementation such as top management commitment, expertise training program and financial support. Strong top management commitment, organisation culture, and employee training program are success factors for implementing lean in industries (Vidyadhar et al. 2016; Sangwan, Bhamu, and Mehta 2014; Bakas, Govaert, and Van Landeghem 2011). Lean management system effectively supported by top management in industries (Rose, Deros, and Rahman 2010). Lean manufacturing is contributing to economic and social aspects of sustainable manufacturing by reducing waste in the process. At inspection stage, defect detection is not correct methodology for quality improvement. During manufacturing of product, defects could be controlled by implementation of lean techniques (Gunasekaran and Spalanzani 2012). A lean tool helps in fasten the process and increase the speed of qualitative production. As summarised earlier India is experiencing severe environmental degradation due to the economy struggles of supply meeting the demand. With increasing urbanisation and proportionate increase in material wastes, lean manufacturing models are the need of the hour in India.

2.2. Sustainable manufacturing in India

For natural resources, conservation and fulfil growing energy demand of people researchers and practitioners and the governing bodies have begun to focus on initiatives concerning about environmental effect of products, sustainable regulations and thus developed the concept of sustainable manufacturing. The impacts of manufacturing have been identified by organisations such as the Intergovernmental Panel for Climate Change (IPCC, 2014). Among all the economic sectors in India, the automobile sector is a large contributor to GHG emission though production and consumption of motorised vehicles. Based on the AMP 2026 report by Auto Tech Review (Automotive Mission Plan 2016-2026 – A Curtain Raiser, 2015), it is estimated that Indian automotive sectors will contribute more than 12% of the overall GDP of the country. But the automobile industry with huge number of human resources employed, face many environmental challenges like deteriorating air quality, contributing to global warming, and ineffective handling end of life automobiles (Orsato and Wells 2007). These environmental challenges and governmental globalisation policies have forced many automotive firms to shift towards Sustainable manufacturing. Sustainable manufacturing helps in improving resource efficiency and cleaner production, which directly relate with economic conditions (Vimal, Vinodh, and Gurumurthy 2017). Sangwan (2011) has explored benefits of green manufacturing concerning quality and life of the product. Sustainability model for performance measurement and inter-relationship factors has been explained by researchers (Jayakrishna, Vinodh, and Anish 2016). Sustainable manufacturing can help in enhancing market share, and a brand image (Agan, Acar, and Borodin 2013). Govindan, Diabat, and Shankar (2015) analysed the factors for green manufacturing implementation by a survey of 120 leading firms in India, and found a result that basic of green manufacturing was missing there. Mittal et al. (2012) focused on future legal requirement towards green manufacturing amongst CSFs in developing industries. Competitiveness, brand images (Ghazilla et al. 2015), high production cost and environmental policies (Luken and Van Rompaey 2008) are found CSFs for Sustainable Manufacturing. Green technologies are capable of meeting product requirements and ensure minimum environmental impact. In sustainability minimising, only the environmental impact is not significant. Industry growth line linked with economic, social and environmental aspects of sustainable manufacturing. For understanding current and future state of any industry, sustainable manufacturing aspects must be covered. As of now, sustainable manufacturing in India is in infancy and proper framework or implementation road map is unavailable. Though sustainable manufacturing involves creation and distribution of innovative products and services that minimises resources; eliminates toxic substances; and reduces greenhouse gases across the entire life cycle of products and services, it can be seen as a parallel to Lean manufacturing concept. Though they do not match exactly they both work towards a sustainable development. This leads us with the idea of proposing Sustainable lean manufacturing for the Indian automobile industry.

2.3. Sustainable lean manufacturing (SLM)

When sustainability was introduced with lean manufacturing, the most common questions were how lean helps in the social development and environment control by reducing waste of resources, energy used and economic growth for organisations. Safety at workplace, operational and environmental dimensions have been targeted in sustainable lean manufacturing (Garza-Reyes 2015; Kurdve et al. 2014; Pampanelli, Found, and Bernardes 2014). SLM decision is based on time of process, quality of product, effective utilisation of resources and cost of product along with environmental performance (Salwa et al. 2008). Environmental impact on production industry can be controlled by lean tools and techniques. Environment impact of manufacturing process was found significant before and after lean techniques implementation in industries (Vimal and Vinodh 2013). Social responsibility activity is an important addition for SLM implementation in the automobile industry, and through this, industry’s quality management system could be improved to the next level of excellence (Habidin et al. 2017). Lean impact social aspect indirectly by reducing stress at the workforce, better space utilisation, developing individual skills by training and motivate in small-small improvements (Hines et al. 2008). For improving environmental, social and economic performance, business organisations are adopting sustainable lean manufacturing processes and product. Researcher already explains that lean has a strong contribution in the sustainable development of organisation (Caldera et al. 2017). Lean and green initiatives are correlating each other regarding actions and outcomes from them (Sajan et al. 2016; Galeazzo, Furlan, and Vinelli 2014; Dües, Tan, and Lim 2013; Larson and Greenwood 2004). According to Diaz-Elsayed et al. (2013), sustainable lean strategies have an impact on 11% of production costs for apart in the automotive industry. Many researchers explained conceptualise model for sustainable manufacturing/lean manufacturing/relationship between lean and green manufacturing/sustainable manufacturing impacts and aspects/sustainable lean practices (Caldera et al. 2017; Jabbour et al. 2013). For sustainable lean manufacturing implementation, conceptual model may be explored and identify factors, which are helping in SLM implementation in the automobile industry. For SLM implementation in the business model, CSFs need to be identified. Many researchers explained CSFs for sustainable lean manufacturing in Table 1.

Table 1. Critical success factors for sustainable lean manufacturing implication for economy, social and environment.

Factors for sustainable lean	Economy	Social	Environment
Top management involvement	Awareness of operational cost and wages shared across the organisation ((Aboelmaged 2018), (Sangwan, Bhamu, and Mehta 2014), (Rose, Deros, and Ab Rahman 2014), (Djassemi 2014), (Bergmiller and McCright 2009b))	Society development through knowledge sharing and budget for CSR activities ((Jadhav, Mantha, and Rane 2014), (Panizzolo et al. 2012), (Bakas, Govaert, and Van Landeghem 2011))	Helps in the utilisation of natural resources and control environment condition ((Nordin, Deros, and Wahab 2010), (Bergmiller and McCright 2009b), (Dowlatshahi and Taham 2009), (Achanga et al., 2006))
Brand value	Right decision in finance and cost investment towards new initiatives (Dora et al. 2013)	Helps in CSR activities which improve society (Bakas, Govaert, and Van Landeghem 2011)	Follow legal requirements and force to compliance environmental requirements (Rose, Deros, and Rahman 2010)
Multiskilling	Can be ready to handle new technology (Sangwan, Bhamu, and Mehta 2014), (Panizzolo et al. 2012)	Help for relation building and resource management (Panizzolo et al. 2012)	Participation in control environment regulation activities (Bhasin 2012), (Singh, Garg, and Sharma 2010),
Machine condition	Impact on total breakdown losses and time (Dora et al. 2013)	Human suffering from the worst condition (Singh, Garg, and Sharma 2010)	Control total natural resources depend on the machine (Rose, Deros, and Rahman 2010)
Working Culture	Workers work towards cost competition (Mittal and Sangwan, 2015), (Ghazilla et al. 2015),	Society improvement through improved culture (Mittal et al. 2013), (Bey, Hauschild, and McAloone 2013),	Healthy culture create a good environment (Studer et al. 2006)
Self-respondent	Involvement in a cost-effective strategy (Bakas, Govaert, and Van Landeghem 2011),	Responding towards the work culture (Rose, Deros, and Rahman 2010)	Create healthy environment (Rose, Deros, and Rahman 2010)
Public awareness	Understanding of economy (Sangwan, Bhamu, and Mehta 2014)	Awareness towards requirement in society (Bhasin 2012)	Contribution in green initiatives (Achanga et al., 2006)
Employee training	Utilisation of knowledge in improvement activities (Aboelmaged 2018)	Overall development in society (Mittal and Sangwan, 2015), (Mittal et al. 2013)	Usages of natural resources and optimum utilisation (Singh, Singh, and Dhingra 2012)
Current legal regulations	Help in the understanding of losses and benefits (Ghazilla et al. 2015),	Focus on social activity (Mittal and Sangwan 2014a), (Bey, Hauschild, and McAloone 2013), (Mittal et al. 2012)	Pollution control action created to prevent environment (Walker et al., 2008), (Luken and Van Rompaey 2008)
Review mechanism	Strategy revision done based on a review (Ghazilla et al. 2015), (Mittal et al. 2013)	Society up-gradation through gap analysis (Bey, Hauschild, and McAloone 2013)	Controlling environment conditions covered in the review (Singh, Singh, and Dhingra 2012)
Work Standardisation	Focus on defect reduction (Dowlatshahi and Taham 2009)	Control work area (Dowlatshahi and Taham 2009)	Effect on environment condition to sustain (Dowlatshahi and Taham 2009)
Cost competitive strategy	Increment in profitability (Aboelmaged 2018)	Contribution in society development (Mittal and Sangwan, 2015), (Ghazilla et al. 2015), (Walker et al., 2008)	Green initiative towards the environment (Luken and Van Rompaey 2008), (Thomas et al. 2012), (Soosay et al. 2016)
Employee Motivation	The effort towards improvement actions (Ghazilla et al. 2015)	Action for society improvement (Mittal and Sangwan 2014a), (Mittal et al. 2013),	Helps in reduction of pollutions (Bey, Hauschild, and McAloone 2013), (Bergmiller and McCright 2009b), (Fatma Pakdil and Leonard 2015)
Usage of upgraded technology	Cost reduced through multi-operation (Sangwan, Bhamu, and Mehta 2014)	It reduces strain in the working area (Dora et al. 2013), (Panizzolo et al. 2012)	Technology helps in reducing pollution (Venugopal and Saleeshya 2019)
Future legal regulation	Understanding of coming regulation to drop in manufacturing (Mittal and Sangwan, 2015)	Activity planned for society (Mittal and Sangwan, 2015),	Pollution level considered for actions (Ghazilla et al. 2015)

Many researchers explained about factors (employee motivation, operator training, upgraded technology usages, employee involvement, public awareness), which are affecting society and the environment by implementing sustainable lean manufacturing (Aboelmaged 2018; Mittal and Sangwan 2015; Ghazilla et al. 2015; Walker et al. 2008; Luken and Van Rompaey 2008; Thomas et al. 2012; Soosay et al. 2016). Mittal et al. (2016) explained factors for sustainable lean manufacturing as management involvement; ready to change has helped in integrated cost reduction. Ministry of Micro, Small, and Medium Enterprises (MSME) is also explaining the initiatives like lean manufacturing competitive scheme and ISO 14,000 certifications. The strategies of sustainable lean organisations have the aim to waste minimisation, which they result in to reduce carbon footprints, improve brand value and productivity improvement which ensure environmental, social and economic benefits.

From above literature review, various facts of lean manufacturing exist for industries but no structured way of sustainable lean manufacturing executed by researchers for the automobile industry. Some of the researchers also stated that lean is not directly co-related with environment aspect as lean known for customer value. Although Japanese auto-manufacturing industry started manufacturing of hybrid engines and usage of the recycling process is lean thinking towards environment sustainability (Carneiro et al. 2012). Government policies and international standards force to adopt systems and evaluate effective sustainable results (The government of India, 2011). The changes in market scenario are on fast track as technology upgraded day-by-day to meet customers’ requirement. To make agile production process in the automobile industry, SLM is mandatory to implement. Indian market is changing from diesel to hybrid engines and in process to qualify the steps of Bharat Stage VI (BSVI) level. Government has introduced subsidies on electric vehicle, which directly hit to petrol two wheeler as well as four wheeler diesel segment vehicles. This is difficult stage for industries, which are not following SLM techniques so to consist improvement in growth every automobile (medium, small and large industries are to in line with sustainable manufacturing.

3. Problem description

In a competitive market, the customer expects a product with less cost that fulfils all needs. Today all manufacturing companies are having a lot of pressure from the government to fulfil legal requirements. Legal requirements now diversify regarding pollution, employee welfare, social welfare and growth rate (economy) also. These requirements belong to sustainable manufacturing. Lean is the process, which helps to get sustainability in the organisation and in the integration of process efficiency (on-time delivery, minimum cost, best quality) (Kim and Bae 2007). Rethinking the growth for long-term prosperity, Ellen MacArthur foundation (2016), reported that India would bring in benefits about 30% of current GDP and can lower 44% of the emissions by 2050 by adopting sustainable development approaches. These benefits can be achieved by launching and enforcing sustainable manufacturing initiatives to build resource effective systems for growth and development (Ellen MacArthur foundation 2016). India is witnessing an increasing GDP of approximately 6% along with its resource consumption increasing at a rate of around 5%. India has ranked world’s 6th in terms of GDP recently, but India is not well positioned to handle the growing resource scarcity to sustain a steady growth in future. Indian government has also begun to focus more on resource efficiency and extended the investments towards sustainable manufacturing and Industry 4.0. (Government of India, 2015)

Currently, only about 10% of the automotive industry in India are actually on a lean and sustainability framework because businesses are still deciding whether to adopt sustainable measures or not. With increase in young working population, India can achieve its full manufacturing potential over the next few decades. The AMP 2016–26 has set targets for the Indian Automotive industry to become one among top three nations in automobile production by the year 2026. Therefore, India needs to ensure that its manufacturing process, approaches and even cities become sustainable by backing lean and sustainable manufacturing in India. In order to meet these requirements, organisations are struggling to identify the CSFs and face problem while adopting sustainability. Concerning the literature review, researchers have identified the factors for lean or sustainable manufacturing and not focused on a particular sector (Naslund 2013). In the Indian automobile industry, customers are being shifted towards comprehensive pillars like safety, quality, cost, and environment. In manufacturing processes, there are many direct/indirect factors, which impact efficiency and product quality. Now the problem is how to implement SLM in the automobile industry and modelling of CSFs for sustainable lean manufacturing implementation. Also understanding the relationships between the factors is necessary to develop a successful implementation roadmap. Hence, our research aims in addressing this problem.

4. Research approach

There are different methodologies for the analysis of CSFs available in the literature. This study aims to define the relationship between the various success factors. It establishes relationships among the factors based on experts’ opinions, which improve internal results (Diabat and Govindan 2011).Singhal et al. (2018) used ISM methodology is used for identifying obstacles and affecting manufacturing practices in India. ISM approach has been used for analysing the CSR issues after the supplier selection process (Threshkumar et al. 2014). For adoption of industry 4.0 in Indian manufacturing industry, barriers driving power and dependence power are analysed by ISM approach (Sachin et al. 2018). Rakesh, Bhaskar, and Gardas (2017) explained lean practices in supply chain, which helps in improving overall performance through ISM methodology usages. The detailed ISM steps are presented in Figure 1. Hence, ISM technique is used for solving such an industrial decision-making problem. Several researchers have used ISM methodology in their research problem in previous years by practitioners, and findings are aligned with solution as shown in Figures 2 and 3. As shown in Figure 2; after year 2015 usage application of ISM methodology increased year on year. Bond et al. (2019) used Interpretive structural modelling to understand JIT practices in manufacturing firm. For this study, Industrialist feedbacks were required and sample data from different scale of industries was mandatory to conclude steps of SLM implementation. For using practical experience and method for step down, the complicated system in simplify system ISM methodology is preferred (Gorvett and Lui 2006). And a multilevel model for CSFs will also helpful to understand the inter-relationships among them (Hachicha and Elmsalmi 2014).

Figure 1. Research flow chart for ISM study.

Figure 2. ISM application used by researchers (year wise).

Figure 3. Journal wise ISM publications.

Hence, ISM methodology is found more appropriate for this study. CSFs listed through literature review and put in questionnaire survey to get opinion of experts. Option was given in questionnaire to add more CSF for SLM implementation in the Indian automobile industry. The step of the methodology followed in this study is shown in Figure 4. This methodology is discussed in Sections 4.1 and 4.2.

Figure 4. Flowchart for analysing the critical success factors for SLM implementation.

In this study, 15 CSFs were identified from previously published research papers by International and National publishers by using keywords ‘Sustainable/Lean manufacturing + Critical success factor’ in multimedia like science direct, IEEE, Springer, emerald. Lean manufacturing approach has been understood during gemba in industries. Lean practices found in place at medium scale and capitalist thinking about sustainable results in operations. Level of the industry also relates to lean practices adoption (Yadav et al., 2010). Majorly OEMs has established their operational process in a lean manner and now they are moving towards sustainability. Tier 1 organisation has direct contact with OEMs resulting in educating and adopting lean practices at full pace. Tier 2 organisation links with Tier 1 manufacturing processes, and all lean practice depend on to whom they are supplying material. Tier 3 organisations are in the beginning phase with Tier 2 growth, and very small practices are adopting in the year on years. The rate of improvement found very slow at Tier 3 industries.

4.1. Questionnaire development and data collection

Face to face dialogue method was selected to evaluate the importance of the key roles that have been found through literature review. A postal survey questionnaire was used as the research instrument. An initial pilot run was carried out with a group of 20 targeted respondents for questionnaire review and feedback. The questionnaire has been focused on the importance of subfactors that clarified from the literature review. It identifies the respondents’ perception of the importance of key roles in sustainable lean manufacturing. Experts requested for rating the factors for SLM based on Likert scale as given in Table 2.

Table 2. Likert scale rating.

Scale	Rating
5	Most effective
4	Very effective
3	Effective
2	Moderately effective
1	Not effective

For this study, experts’ selection was done based on their competencies as minimum education considering bachelor degree in industrial engineering or related filed; practical/academic experience more than 10 years in lean implementation; minimum designation considered as department manager and handling team of more than 10 members; industry in which they are working must be using lean tool and techniques for continuous improvement. As shown in Figure 4, around 125 automobile industries visited across India. Top management reviews were identified new CSFs for SLM implementation. After consent of experts, top management review merged with top management involvement. This study is helping industrialist for their stable process and product knowledge. The respondents searched for organisations that are directly related to process and product as production manager, quality manager, Management Information System (MIS) officers, store managers and plant manager. Many organisations are working with lean practices and having a partial implementation of lean tools. Totally, 83 effective experts were contacted out of 40 responses (having more than 20 years experience) were considered for the study. According to Emory and Cooper (1991) responses ranging from 20 to 100 found appropriate for pilot study. Selected responses received from the experts having quality experience of lean implementation in industries. A meeting scheduled with experts after continuous requesting emails and face to face questionnaire were discussed. Actual shop floor implementation journey analysed during gemba visit. Brainstorming session with industry experts and 15 factors found relevant to Indian industry and selected for this study. For statistical analysis, these CSFs further merge concerning their base in manufacturing. Nine CSFs (top management, employee, technology, machine, culture, legal regulation, government, strategy and financial review) consider for statistical analysis. The results of statistical analysis of the questionnaire survey to rate the factors in working experience in Indian manufacturing industry have been shown in Table 3.

Table 3. Statistical analysis of factors for SLM Implementation.

CSFs	Mean	S.D.	Rank
(i). Top management	4.177	0.8988	I
(ii). Employee	3.869	0.8136	VIII
(iii). Technology	3.934	0.9543	1V
(iv). Machine	4.001	0.9615	11
(v).Culture	3.925	0.9387	V
(vi). Legal Regulation	3.906	0.9063	VI
(vii). Government	3.897	0.8895	VII
(viii). Strategy	3.962	0.9802	111
(ix). Financial review	3.859	0.9054	IX

4.2. Interpretive structural modelling (ISM)

Interpretive Structural Modelling helps us in the arrangement of factors to resolve complexity (Mandal and Deshmukh 1994; Jharkharia and Shankar 2005; Garbie 2017; Thanki and Thakkar 2018). It is also a useful tool for concluding the relationship among the factor to understand the problem (Warfield, 1974; Sage, 1977). ISM methodology has been explained through various steps as:

• List of factors prepared which participate to implement SLM in Indian industries.

• The contextual relationship of factors has been examined.

• Structural Self-Interaction Matrix is derived for factors; show an interdependent relationship with two factors.

• An initial reachability matrix is derived from SSIM and it co-relates transitivity among factors. For transitivity of contextual relationship, some assumptions were defined in ISM. These defined as A factor is related to B factor, and factor B is related to C factor, then factor A is directly related to factor C.

• Reachability matrix explained in Step 4, divided into different levels.

• ISM model is derived by replacing factor end with declarations.

ISM methodology used by many researchers to identify the contextual relationship of variables. Brainstorming sessions held with industrial and academia experts to draw the relationship among CSFs. Direct relationship matrices of factors for energy conservation in Indian cement industry analysed through ISM (Saxena et al. 1990). For supplier selection, ISM methodology was used by researchers and found efficient results towards rating the supplier. To develop a model for reverse, SCM ISM methodology was used in Indian scenario (Ravi and Shankar 2005). Raj et al. (2008) also used ISM application for implementation of flexible manufacturing system with the help of driving and dependent variables. Hence, ISM methodology found suitable for this study to identify the CSFs for SLM implementation in the Indian automobile industry.

4.3. Structural self-interaction matrix (SSIM) and reachability matrix

In a current study for the deriving relationship among factors of SLM, 40 experts were referred. These experts from the academia and Industry had rich experience in sustainable and lean manufacturing implementation in Indian industries. With respect to their view, the contextual relationship has been developed in SSIM matrix. Four codes have been used to define the direction of the relationship between the factors (i and j):

V- Factor i will relate to factor j;

A- Factor j will relate to factor i;

X- Factor i and j will relate to each other; and

O- Factor i and j are unrelated.

The resulting Table 4 would describe the use of the symbols V, A, X and O in SSIM. The SSIM has been converted into a binary matrix and is called the initial reachability matrix by converting the symbol V, A, X and O by 0 and 1. The final reachability matrix is obtained by incorporating the transitivity as explained in the ISM methodology. The final reachability matrix has been explained in Table 5.

Table 4. Structural Self Interaction Matrix.

Variables	15	14	13	12	11	10	9	8	7	6	5	4	3	2
1	V	V	X	X	V	V	V	X	V	V	V	V	V	V
2	A	A	A	A	A	A	A	A	A	A	A	A	A
3	X	X	O	O	V	A	V	A	V	A	A	X
4	X	X	A	A	V	A	V	A	V	A	A
5	O	V	A	A	V	V	V	A	V	V
6	O	O	A	O	O	O	O	A	V
7	A	A	A	A	V	A	A	A
8	V	V	X	X	V	V	V
9	A	A	O	O	V	A
10	O	A	A	A	V
11	O	A	A	A
12	V	V	X
13	V	V
14	O

Table 5. Final Reachability Matrix.

Variables	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	DRIVE Power
1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	15
2	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	1
3	0	1	1	1	0	0	1	0	1	0	1	0	0	1	1	8
4	0	1	1	1	0	0	1	0	1	0	1	0	0	1	1	8
5	0	1	1	1	1	1	1	0	1	1	1	0	0	1	0	10
6	0	1	1	1	0	1	1	0	0	0	0	0	0	0	0	5
7	0	1	0	0	0	0	1	0	0	0	1	0	0	0	0	3
8	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	15
9	0	1	0	0	0	0	1	0	1	0	1	0	0	0	0	4
10	0	1	1	1	0	0	1	0	1	1	1	0	0	0	0	7
11	0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	2
12	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	15
13	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	15
14	0	1	1	1	0	0	1	0	1	1	1	0	0	1	0	8
15	0	1	1	1	0	0	1	0	1	0	0	0	0	0	1	6
Dependence	4	15	11	11	5	6	13	4	11	7	12	4	4	8	7

4.4. Level partitions

From final reachability matrix, reachability set and antecedent set for each factor have been found (Warfield 1974). Consequently, the intersection set of these groups have been derived for all factors. Top-level factor in ISM hierarchy has been derived from reachability set, and the intersection set values. ‘Brand value’ has been found at level 1 from Table 6. Each factor has been found out by the iteration.

Table 6. Partitioning of Variables.

Variables	Reachability Set	Antecedent Set	Intersection Set	level
1	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15	1,8,12,13	1,8,12,13	X
2	2	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15	2	I
3	2,3,4,7,9,11,14,15	1,3,4,5,6,8,10,12,13,14,15	3,4,14,15	VIII
4	2,3,4,7,9,11,14,15	1,3,4,5,6,8,10,12,13,14,15	3,4,14,15	VIII
5	2,3,4,5,6,7,9,10,11,14	1,5,8,12,13	5	IX
6	2,3,4,6,7	1,5,6,8,12,13	6	V
7	2,7,11	1,3,4,5,6,7,8,9,10,12,13,14,15	7	III
8	1,2,3,4,5,7,8,9,10,11,12,13,14,15	1,8,12,13	1,8,12,13	X
9	2,7,9,11	1,3,4,5,6,8,9,10,12,13,14,15	9	IV
10	2,3,4,7,9,10,11	1,5,6,8,10,12,13,14,	10	VII
11	2,11	1,3,4,5,6,7,8,9,10,11,12,13,14,	11	II
12	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15	1,8,12,13	1,8,12,13	X
13	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15	1,8,12,13	1,8,12,13	X
14	2,3,4,7,9,10,11,14	1,5,8,12,13,14	14	VIII
15	2,3,4,7,9,,15	1,8,12,13,15	15	VI

5. Formation of ISM-based model

After adding a statement in place of node and transitivity link, the ISM model is developed which is shown in Figure 5. It has been stated from Figure 5 that ‘Top management commitment; Future legal regulation; Cost competitive strategy, and Employee Motivation’ has been very significant for SLM implementation in the Indian industry as it comes at the base of the ISM hierarchy. ‘Brand value’ has been identified as the top-level factor in ISM.

Figure 5. ISM-based model of CSFS for SLM implementation.

After ISM model formation, same has been discussed with industry experts. Among 40 industries visited and elaborate ISM model with production managers, plant heads and top managements for SLM implementation. It is found very optimum model for arranging CSFs in SLM strategy. Industrial researchers also validate this model for Indian industry to make lean and sustainable results.

6. MIC-MAC analysis

From driving power and dependence power MIC MAC analysis has been carried out. In final reachability matrix driving power and dependence, power has also been added. By using the calculation of driving and dependence power, MIC MAC analysis classifies these factors into four sets of autonomous, dependent, linkage and driver factors as explained below:

• The first set has autonomous factors that have weak dependence and driver power. Self- Respondent, Future legal regulation, and Review mechanism have been recognised in this set (autonomous factor).

• The second set consists of the dependent factors that have weak driver power but strong dependence. Brand value, Public awareness, Current legal regulation, Work standardisation have been recognised as a dependent factor.

• The third set has the linkage factors that have strong driver power and dependence power. In this study, Multiskilling and machine condition have been identified as linkage factors.

• The fourth set is having the independent factors having strong driving power but weak dependence. Top management involvement, Working Culture, Cost competitive strategy, Employee motivation, Usage of upgraded technology and employee training have been recognised as driver factors.

This driver power-dependence diagram has been explained in Figure 6.

Figure 6. Driving power and dependence power diagram of critical success factors for SLM adoption.

7. Discussions

The SLM has been identified as a strategy for continual improvement in today business era. Both product and process have been considered for improvement in this strategy. In this study, 15 CSFs have been identified hose help in the implementation of SLM in the automobile industry. Moreover, an ISM model is also derived, which identifies the relationship among 15 factors to help in SLM implementation. In Section 6, CSFs have analysed which strongly drive SLM implementation in the automobile industry. CSFs relate with economics, social and environmental aspects of the sustainable manufacturing. Today’s market is growing with a combination of multi-variant combination to meet customer demand.

7.1 Inter-relationships and impact of CSFs on SLM implementation in Indian industries

7.1.1. Top management involvement – >working culture, employee training, cost competitive strategy, employee motivation

Top management leads to improve working culture through monthly awareness meetings, employee birthday celebration, rewards for best results. By management review and involvement, new directions have decided to reach at the next level of achievement by team building, training and employee motivation. Top management focus is most important to lead SLM implementation in industries. Management initiatives directly impact on manufacturing activity by involvement and commitment (Aboelmaged 2018). Top management has been considered driver CSFs for sustainable lean manufacturing implementation.

7.1.2 Employee training < – –> cost competitive strategy, top management involvement

Employee training started to initiate cost competitive strategies in organisation also driven by top management. Without training to employee, no strategy works in any organisation. Employee training is also a critical factor for enhancing the skills of working hands, which will directly affect the quality of their products. Cultural and training changes are found important for economic design and environmental results. Employee training is also an important support to working culture and new cost strategy. Through training employee thinking diversify and make positive impact towards new ideas. Employee satisfaction is found critical in achieving performance objective as positive attitude that comes in the workforce (Ghazilla et al. 2015). Business sustainability initiatives provided guidance and support to the industry to develop its improvement projects for shop floor development. The employee is considered as a base for startup and any initiatives regarding improvement activities. Employee motivation support to working culture and interlinked with cost competitive strategy.

7.1.3. Working culture < – -> usage of upgraded technology, multitasking and machine condition

Implementation of the lean process failed in startup phase due to organisational culture was not considered by leading team (Mittal and Sangwan 2015). To overcome past failure, working culture considered as CSFs, and it is found as a driving factor. Working culture support to multiskilling and maintained machine condition by daily machine clean and total preventive maintenance system. Working culture helps in competitive thinking and team building activity for problem solving. Machine condition improves equipment efficiency and sustain the business performance by producing as per customer demand (Dora et al. 2013).

7.1.4. Usage of upgraded technology, multitasking and machine condition – ->review mechanism

Activities completion of organisation links to review mechanism process of the organisation. Review mechanism made from level 1 to top level of the organisation based on criticality of the task. Review mechanism is the most important CSF to meet organisation vision and mission.

7.1.5. Review mechanism – ->future legal regulations, current legal regulation, public awareness and work standardisation

Review mechanism helps in understanding of future and current legal regulations for the organisation. Non-conformance to legal regulation leads to shut of any organisation. Legal regulations are revising day-by-day to improve in environmental conditions. Adherence of regulation is useful for society as well as for industry brand value. Customers consider legal regulation as first checkpoint in their checklist for startup of the new business and collaboration. Market share can be impacted if industry get shutdown due to legal authority.

7.1.6. Future legal regulations, current legal regulation, public awareness and work standardisation – – > brand value

Adherence of legal regulation and work standardization helps in improving level of organisation branding. Brand value helps in getting involved with a market leader and shares the best practices in the group. Brand value is supported by working culture of industry; usages of upgraded technology; public awareness and adherence of current/future legal regulations.

In automobile industry 6M (Man, Machine, Material, Method, Measurement, and Management) are consider as the basis for the startup. Every ‘M’ has their equivalent role in the manufacturing sector. First M- man checked for two aspects (i) number of man power required; (ii)skill level of manpower. Second M-machine assessed for product manufacturing or machine condition, which meets customer requirements. Third M-material checked based on availability and properties as per product requirement. Fourth M-method is assessed based on product design, customer requirement and lean applicability. Fifth M-measurement stands for measuring instrument availability to check final product followed by sixth M-management interest towards particular business strategy. 6M assessment linked to CSFs and return on investment get increased.

CSFs have been a link with 6M for SLM implementation in the automobile industry. As market competition is increasing to meet customer demand in aspects of cost, quality and time (Bey, Hauschild, and McAloone 2013).

For large and medium size manufacturers brand image is found important factors and affect their multinational business perspective also. With agreement assignments, firms announce their achievements and initiatives for environmental performance to get recognition from stakeholders and government. Management is always concerned about their market image and takes consultant helps to decide the strategy for growth improvement. Work standardisation is also helping in standardising of the manufacturing system to promote and validate the capability of the manufacturer. Industries are now progressing towards business sustainability to get the strong financial position.

Automobiles industry is playing a major role in influencing the economy of the nations and providing engagement chances and better living arrangement for society. The sustainability performances are also interrelated with each other. It is found a significant effect on environmental sustainability to economic and social performances aspects of manufacturing plants. Small-scale industries are having a different reason for adopting this situation, which is lack of resources, management is not interested to adopt change and reluctance to make required investments for lean implementation. And it is also necessary to act with driver factors to implement SLM in an automobile industry. These are strongly impacting the starting thrust for any action which lead towards business orientation and make an economic effect in the system. In continuation of driving factors analysis, it is also found critical to assess factor coordination, which can initiate the action inline of SLM implementation. In this study, path has evaluated for implementing all aspects of sustainability as economic, social and environmental with lean actions to make an effective impact on manufacturing system for automobile industry.

8. Conclusions and recommendations

As India is growing fast in the automobile sector, and many automobile industrial hubs introduced with almost all major original equipment manufacturers (OEMs) as Maruti Suzuki, Suzuki Motor Corp., Ford, Honda, BMW, Mercedes, JCB, Escorts, Daimler, ISUZU, Hero Moto Corp., Kia, Mahindra and Mahindra, Force, TVS, Bajaj Volkswagen, Tata Motors, Ashok Leyland, are having large supplier base. As major OEMs have their presence worldwide, they have exposure to lean and sustainable manufacturing. India is being considered as competitive cost market, and this is the challenge for many OEMs to survive. As major assemble parts OEMs are buying from Tier 1 and Tier 2 suppliers and assembly on their platform. So being competitive cost market, OEMs have to focus on their suppliers towards waste reduction through lean and sustainable manufacturing. The brief conclusion of the study is:

• Top management considers as a driver for any organisation as his vision, decision, commitment, which will help to meet the requirement of the customer.

• Working culture, employee training, and upgraded technology also will have impact on business processes.

• This study will help in decision making during SLM implementation in the Indian automobile industry.

• 6M assessment must be carried out during new business development stage for better economic and socio results.

• Industries should participate at national/international level in case study competition/business exhibition to have best practice sharing maintained brand image.

Government is also taking the initiative towards green manufacturing because of increasing pollution. For controlling pollution, many laws and standards present for an automobile manufacturer and they must go through these audits. By SLM implementation automobile manufacturer can survive in this competitive era. This study will help in decision making for SLM implementation to achieve qualitative product, on-time delivery, and less cost. It may be helpful in rewards and recognition from the government through various quality and environment schemes like ZED, Green corp. Updated technology adoption will be also helpful in meeting customer demand and sustainable economy. Employee motivation and development support organisation to meet expectation and deliver more than ability. Positive results show this role is having a strong impact on the industry. This study will help in identification of resources to make industry lean and sustainable. Environmental conditions will be improved through SLM implementation using ISM model. With the help of this study, an automobile manufacturer can release their pressure to explore business in the competitive market.

8.1. Limitation and future scope of the study

In this study, CSF’s relationship was derived with the help of ISM methodology for SLM implementation only in the Indian automobile industry. In further scope, this study may be extended to identification of CSFs for SLM implementation in different manufacturing industries. Result and effect of SLM implementation may also diversify in manufacturing industries. A case study may explore by validating ISM model in the Indian automobile industry for SLM implementation. Looking ahead implication of this study may be more explored for academia and industries. Business leaders can identify more opportunities to strengthen their processes by sustainable lean manufacturing.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Naveen Kumar

Naveen Kumar is pursuing his PhD in the Department of Mechanical Engineering, The NorthCap University. He completed his master’s in Mechanical Engineering from Maharishi Dayanand University, Rohtak, India. He accomplished his master’s in Mechanical Engineering with specialization in Manufacturing and Automation, respectively. He has ten years of Industrial experience with reputed OEMs’. He has been associated with various facets of quality systems improvement and optimization over the last two years. His contribution towards publication of research so far has been concise and exposed to ground-level implementation at the medium- and small-scale industries in India. He has completed more than sixty projects with tier 1 industries. His specific areas of interest are industrial engineering, supply chain management, green supply chain management, lean manufacturing, six sigma, design of experiments, etc.

K. Mathiyazhagan

K. Mathiyazhagan is currently working as an Associate Professor in the Department of Mechanical Engineering, Amity University, Noida, UP, India. He did his Ph.D in the Department of Production Engineering, National Institute of Technology – Tiruchirappalli, Tamilnadu. In addition to the Ph.D work, he went to the University of Southern Denmark, Denmark” four months as a visiting research scholar. He has more than 70 International publications and Associate Editor of Environment, Development and Sustainability - Springer and one international book chapter in the Taylor and Francis. Recently one of his paper awarded as Excellence Citation Award by Emerald Publisher Ltd.  Also he is guest editor of many special issues in International journals.

Deepak Mathivathanan

Deepak Mathivathanan is a Lecturer at University of Southern Denmark working for the Department of Technology and Innovation. He has received his PhD degree in the field of Sustainable supply chain management from National Institute of Technology, Tiruchirappalli, India. His research interests include Sustainable supply chain management, Circular economy and Multi criteria decision making. He can be contacted at: [email protected].