1. Introduction
According to Workplace Safety and Health Guidelines, an Occupational Disease (OD) is contracted as a result of exposure to risk factors in a working environment [
1]. The incidence of occupational disease is increasing among workers in production sectors [
2]. This issue has received much attention, but only after the United Nations, with their sustainable development goals (SDG), defined sustainable industrialization as one of seventeen goals to alleviate poverty, improve workers’ health, and enhance social prosperity. In connection with the United Nations SDGs, many manufacturing companies in developed countries started providing a safe working environment. However, manufacturing companies, especially small and medium-sized enterprises (SMEs), in developing countries, face challenges in following the ergonomics practice [
3]. Providing an ergonomically designed working environment allows for the manufacturing company to produce quality goods and to enhance the workers’ well-being, thus increasing employee productivity. The SMEs of developing countries, in recent years, have provided a considerable contribution to the economy of most developing nations [
4]. India, a developing country, mainly relies on SMEs to combat problems, such as high unemployment, unstructured business organizations, and a lack of foresighted business policy. Noticeably, these sectors hold a considerable share in a country’s Gross Domestic Product (GDP) and offer employment opportunities for economically weaker sections [
5]. As a result, there are more SMEs in India than large companies [
6]. Although SMEs do provide employment and financial assistance for the economically marginalized and semi-skilled population, most of the SMEs are unaware of sustainable development goals [
7]. As largely known, the sustainability concept covers three areas, including economic, environmental, and social areas. However, most industrial perspectives note their primary concern as economically sustainable success in financial markets [
8]. Due to pressure from the customers for sustainable manufacturing practices and to meet the government’s environmental norms, the manufacturing sector has necessarily started to concentrate on matters of environmental and social sustainability [
9].
Social sustainability is related to the creation of a social system that enables the rise of workers’ wealth and health, and that contributes to the nation’s development; environmental sustainability is related to the minimization of natural resource utilization [
10]. Industrial factors affecting the workers’ health may result in the frequent absenteeism of workers and in the loss of production hours, which hampers the production rate. Hence, there is a need to understand the relationship and synergy between the working environment and workers’ health. The problem in social sustainability occurs mainly in four areas: internal human resources, external populations, stakeholder participation, and social performance issues [
11]. In the four problematic areas, Indian SMEs primarily struggle with the utilization of internal human resources and social performance [
12]. The Bureau of Indian Standards (BIS) states that an industry’s workspace and work environment should be designed in accordance with the anthropometric dimensions of the workforce and environmental firms. However, most of the SMEs do not adhere to these standards; many are unaware of the importance of the ergonomic problems associated with their production [
13]. The SMEs were of the mindset that they can hire workers for a minimum wage who are ready to work in a poor working environment [
14]. Working under such environments may lead to painful disorders in the muscles, joints, nerves, tendons, and soft tissues of the body, which are collectively called “work-related musculoskeletal disorder (WMSD)” [
15]. The majority of the workforce in the manufacturing sector suffers from WMSDs, knowingly or unknowingly, and it results in low productivity [
16,
17].
Recently, in the health and safety management area, the concept of “vision zero” is gaining significant importance [
18]. The concept emphasizes three core aspects, health, safety and well-being of the workers. “Vision Zero” was first introduced by the International Labour Organization (ILO) in Singapore in 2017. There is a perception that “vision zero” will assist in industrial progress towards SDGs. Though the concept was conceived in a constructive manner, reluctance and poor adherence by the business organization puts a big question on the success of the concept [
19]. Additionally, the industrial sectors in developing countries are not even aware of the concept. As a result, the prevalence of occupational accidents and injuries is high in developing countries such as India. In India, there exists a void in understanding the significance of ergonomic issues and its influence on the production capacity of the manufacturing sector [
20].
From the above information, it is apparent that the majority of Indian SMEs are not aware of the synergy between ergonomic importance and productivity. Further, research work on ergonomic problems in the context of developing countries is very scant. In a study carried out by [
21] Bernard et al. (2020), it was reported that the number of occupation-related illness in the Brazilian industrial sector has increased progressively in the last 6 years. Not only in Brazil, but the prevalence of occupational illness is also increasing steeply in many developing countries where the knowledge and significance of ergonomics are meagre. This finding was endorsed by [
22] Olabode et al. (2017) in a study which indicated the absence of strict legislation and reforms as the reason for this. Such an indication suggests the need for potential intervention in industries based on the nature of occupational hazards [
23]. Most of the industries in developing countries, such as India, are unaware of ergonomics and are reluctant to improve the working environment [
24]. The condition is similar in other developing countries such as China and Bangladesh, where socio-economic conditions hamper the improvised ergonomic conditions [
25,
26].
From this perspective, this study intends to identify the critical ergonomic factors that hamper productivity based on symmetry principles. For this, we selected the leather garment industry, which is one of the principal niches of the Indian economy. In connection with this, this research work carries out multiple case studies among workers from five leather garment companies. The reason why a case study in the leather sector is particularly important is because leather exports are expected to be 9 billion by 2020; 2019 figures stand at 5.85 billion (
http://www.makeinindia.com/sector/leather). The findings of the study under Indian leather garments can be used as a benchmark for other developing countries such as China, Indonesia, and Bangladesh as the socio-economic conditions are similar. Additionally, the economies of these countries are significantly enhanced by leather garments. As a matter of fact, it should be noticed that many countries located in Asia are players in the global leather trade. Besides this, we have selected the leather garment industry mainly for two reasons. Firstly, the foreign trade of India largely depends on the leather garment industry. At the same time, this industry faces serious issues such as workers’ safety, health risks, and employee rights. Secondly, this sector is well-established and needs best practices in the social sustainability context to reshape its negative social reputation.
Given the importance of the ergonomic problem in the Indian context, this study addresses the critical gap in the literature. First, the study made a literature review to identify various ergonomic problems faced by workers in a manufacturing background and in the context of developing countries. From the literature review, the study identified 20 critical ergonomic factors and categorized three important categories—occupational disease, industrial environment and personal factors. From the results, the study postulates practical implications, such as providing reasonable pay irrespective of the gender, conducting frequent motivational programs for the workers, and the provision of comfortable and aesthetic working environments, which will reduce ergonomic problems within working environments. Such steps by the industries will assist in the progress towards SDGs.
The justification behind the proposed study is to understand the significance of ergonomic factors and its influence on the production capacity of the manufacturing sector. In this study, Indian leather garments were chosen as a case industry as they contribute significantly to economic development. Additionally, at present, India is on the track of massive development and has one of the most anticipated economies in the world.
From this perspective, this research explores some questions for analysis, as follows:
What are the critical ergonomic factors affecting production in the leather garment industry of India?
What are the vital sustainability-related social implications of ergonomic factors in Indian SMEs?
To reveal the answers to the above research questions, an SPSS statistical software-assisted fuzzy AHP-based symmetrical assessment approach was used. Here, SPSS statistical software was utilized for statistical analysis of the ergonomic factors identified through a literature survey. Then, fuzzy AHP was used to evaluate and prioritize those ergonomic factors. Finally, some implications for attaining social sustainability were suggested.
The remainder of the paper is organized as follows:
Section 2 details the literature review,
Section 3 describes the materials and methods,
Section 4 presents the data evaluation,
Section 5 presents the results,
Section 6 provides discussion. Finally,
Section 7 concludes this paper.
3. Materials and Methods
The research layout of this work is given in
Figure 1. To identify the common ergonomic factors affecting the production rate of leather garment workplaces, we first reviewed relevant papers on various ergonomic factors and their roles/importance in leather garments of different countries; we then collected those common factors (
Table 1).
The data collected need to be reliable and valid for further analyses and future studies. Reliability refers to the degree of consistency. Validity refers to the degree to which the factors considered measure the intended purpose. The reliability of the data was evaluated by calculating Cronbach’s α using SPSS tool. For this, 100 participants (50 males and 50 females), working for not less than 8 years from the five leather garment companies were asked to express their opinions about the importance of the selected ergonomic factors via a five-point Likert’s scale (5–strongly agree, 4—agree, 3—neutral, 2—disagree, and 1—strongly disagree) [
55]. After consolidating the workers’ responses, Cronbach’s α was calculated for the identified ergonomic factors using SPSS statistical software [
66]. The value of cronbach’s α should lie between 0 and 1. In most general cases, a minimum α value of 0.70 is considered as a criterion for establishing internal consistency. Sampling adequacy for a normal distribution was measured by Barlett’s test of sphericity and Kaiser–Mayer–Olkin (KMO) test. In some case—i.e., non-normal distribution—Levene’s test is used instead of Barlett’s test of sphericity. Using Barlett’s test of sphericity, the null hypothesis was eliminated—i.e., the variances are equal for all samples. Statically, the null hypothesis is given as
. The Breusch–Pagan test is conducted to reject the null hypothesis of heteroskedasticity. The KMO value lies between 0 and 1. KMO values between 0.8 and 1 indicate the sampling adequacy [
67]. When the collected data satisfied the validity and reliability test (
Table 2), the ergonomic factors hindering production rate of leather garments were evaluated using FAHP. The factors and sub-factors of ergonomic causing production loss were also evaluated using FAHP.
The statistical results after the deletion of the factors are summarized in
Table 3. The Cronbach’s α value, including all the factors, was 0.877, indicating that the data used for the study were reliable. Additionally, Cronbach’s α value of factors should be noted if the item deleted is less than 0.877. Hence, all factors under study are reliable. As far as the inter-item correlation matrix is considered, it should be noted that all the factor values are greater than 0.3. This indicates that the factors are likely to have common factors.
A combined fuzzy set based AHP using a linguistic scale [
68] is widely used to solve actual-time problems that include human factors as it helps to clear up imprecise information. Generally, there are two types of fuzzy numbers—namely triangular and trapezoidal fuzzy numbers. In this study, trapezoidal fuzzy numbers were preferred over triangular fuzzy numbers as they are more representative of linguistic estimations in ergonomic evaluation. In comparison with triangular fuzzy numbers, the trapezoidal fuzzy numbers offer more choice of expressions. In FAHP, the consistency ratio (CR) was calculated and it must agree with the CR value.
Table 4 shows two tests that measure the data adequacy. The KMO measure of sampling adequacy value in this study was 0.802. High values (close to 1.0) indicate that the factor under study is suitable for further analysis. However, when the value is less than 0.5, the data are not useful for analysis. In our case, the KMO value is 0.802, which is close to 1.0 and, hence, the data are suitable for analysis. Next, the significance level in the Barlett’s test was 0.00 in our case. Small values (less than 0.05) of the significance level indicate that the factor is useful.
Trapezoidal fuzzy numbers are given in
Table 5 [
65]. The scale of significance, given in
Table 5, is used to represent the significance level of each ergonomic factor. In this study, a five-point significance scale, representing the level of each ergonomic factor, is used. Initially, evaluation is made using the significance scale. Later, the significance scale value is converted in the trapezoidal number, given in
Table 5, and evaluated.
Before calculating the weight of the ergonomic factors, the consistency ratio (CR) value has to be calculated (
Table 6). Based on the number of factors, the recommended CR value varies. For the corresponding number of factors, the CI was defined. Only when the calculated CR value was satisfied were the factors subjected to weight calculation.
A trapezoidal fuzzy number, denoted as
, has the following membership function:
where (
m,
n) are called the mode interval of
, and parameters l and u are the lower and upper bound of
, which limits the field of possible calculation. Let us consider two trapezoidal numbers,
and
,
and
. The main operational laws for these two trapezoidal numbers,
and
, are listed below:
Weight Calculations
In this study, trapezoidal fuzzy numbers are used to represent a pair-wise comparison. Here, a 9-point scale is used to represent trapezoidal fuzzy numbers in the pair-wise comparison.
As per the pair-wise comparison, a matrix
is constructed.
where
is the scale of T
i compared with T
j. Similarly, the scale is
when T
j is compared to T
i.
It is necessary to check the consistency of a pair-wise comparison matrix before calculating the weights of sub-factors. To verify the consistency of the pair-wise comparison matrix, fuzzy numbers are improved to crisp numbers. The result of the defuzzified crisp matrix is:
To calculate the consistency index (CI),
has to be calculated. To calculate
,
W′ has to be calculated.
Using Equation (13), the consistency index of the comparison matrix can be calculated.
where
λmax is the largest Eigenvalue of the comparison matrix and
n is the dimension of the matrix.
Let
be the fuzzy pair-wise comparison matrix, where
. The weight can be calculated as follows:
Fuzzy weights can be computed as:
Fuzzy weight vector
can be obtained.
After calculating the individual weights of all the sub-factors within the main factors, the global weight of the factors is calculated. Equation (25) is used to calculate the global weight of the factors.
where
GSij—global score of sub-factors;
CWij—local weight of sub-factors with respect to the main factor;
CWcij —global weight of the main factor.
7. Conclusions
Ergonomic issues faced by the workers within the working environment to a large extent reduce the working efficiency. In some cases, ergonomic issues may bring in severe complexities, such as musculoskeletal disorders (MSDs), breathing difficulties and skin problems. Such complexities may increase the frequency of absenteeism of workers, resulting in decreased production and loss of working hours. Realizing the influence of ergonomic issues in industrial performance, developed countries have started paying significant attention in providing ergonomic free working environments. However, due to a lack of awareness about ergonomic issues and the availability of a cheap workforce, developing countries are not considering ergonomic issues as a serious. Hence, this study intends to identify the ergonomic problems faced by workers in leather garment industries in Southern India. For identifying the ergonomic factors, the extant literature was reviewed, and industrial experts’ opinions were sought. Then, using the SPSS tool, the twenty most influential identified ergonomic factors were validated. The twenty identified factors were classified under three categories. To evaluate the identified ergonomic factors, a multiple case study was carried out in five leather garment companies. The fuzzy AHP method was used to prioritize the identified ergonomic factors. The rankings of the main ergonomic factors using fuzzy AHP were obtained as follows: Industrial environment, Personal factors, and Occupational disease. The factor “industrial environment” secured the highest rank and it needs immediate attention from management in enhancing production rate and also in attaining social sustainability. The sub-factors of ergonomic problems were also prioritized in this study. In this work, the sub-factor of outdated machinery (found within the industrial environment category) secures the first rank in the priority ranking. So, the management of the garment must replace existing outdated machinery with new ergonomically designed machines. A sensitivity analysis was carried out to ensure the priority ranking of sub-factors obtained through fuzzy AHP.
This study has some significant contributions. Firstly, this work imparts knowledge and awareness about the importance of addressing ergonomic issues from the context of the developing nation. Such types of work in developing nation contexts are scant. Secondly, in this work, the validity of the data was assessed using SPSS software by calculating the Cronbach’s and Barlett’s test. In earlier studies, Cronbach’s alone is calculated. Finally, this work has considered and evaluated the role of personal factors in ergonomic issues, a factor not considered in earlier studies.
To overcome the identified ergonomic issues, some possible managerial implications are suggested. Firstly, the industries must replace existing outdated machinery with the latest machines. Machines with adjustable height must be provided as it greatly reduces the occurrence of back pain of the workers. Next, industrial management must pay attention to the provision of hygienic working environments. Providing a hygienic working environment may reduce the workers’ exposure to health hazards. Finally, work schedules with adequate intervals must be provided. Additionally, frequent motivational programs must be conducted to reduce the fatigue of the workers. The findings of this study should not be limited only to the leather garment industry; the findings are applicable to other SMEs, such as handloom weaving companies, spinning mills, or packaging companies in which human and machine interaction is imperative.
Though this study contributes significantly to the literature on ergonomic issues, it also has several limitations. For instance, the ergonomic factors considered and evaluated in this study were collected from the Indian context. So, caution must be exercised while carrying an ergonomic studies considering these factors in other developing countries. Next, this study only evaluates the weight of ergonomic factors.
As a future direction of the study, a study using DEMATEL and ISM may reveal the inter-relationship among these factors, both in an Indian context and in the contexts of other countries. Some of the factors considered in this study may become insignificant in a future study. For instance, the factor “outdated machinery” may become insignificant in future, as India is on a path of development. At present, a lot of manual work is exerted from the workers by industrial management and hence, the study evaluated the factors related to physical health. However, in future, with technological advancement, the study on the ergonomic problem may be more focused on psychological and cognitive factors. Further, with the concept of corporate social responsibility (CSR) gaining attention, the future study of ergonomics may be merged with the CSR concept.