Prioritization of Critical Success Factors in Industrial Waste Management by Environmental Engineers and Employees

Abstract

Today, with the increase in population, technological developments, industrialization and urbanization, problems related to waste management (WM) have become increasingly important to a sustainable and global clean environment. The gradual deterioration of the quality of environmental elements and the increase in environmental problems have caused societies to focus more on environmental problems. Waste management is a form of management that includes the prevention, non-prevention, reuse, recovery, and disposal of domestic, medical, hazardous, and non-hazardous wastes. This study aims to prioritize critical success factors (CSFs), via the Analytical Hierarchy Process (AHP), in industrial waste management and to determine the most important critical success factor. The four main criteria and 23 sub-criteria were scored by the AHP method according to the opinions of five environmental engineers. After determining critical success factors, survey questions were prepared to make employees rank these factors. While the “national/local waste management strategies and policies” factor was the most important critical success factor according to environmental engineers, the most important critical success factor for employees was “enterprise waste management strategies and policies”. In addition, differences in the priorities of CSFs were found in the opinions of employees in different sectors.

1. Introduction

With increasing industrialization, both the diversity and quantity of industrial waste are increasing day by day. In particular, heavy metals and toxic substances contained in industrial waste constitute a problem for human life and ecological balance. Rapid economic growth, technological development, urbanization, population growth, and welfare increases also lead to an increase in the amount of waste produced. According to the National Recycling Strategy Document and Action Plan (2014–2017) of the Ministry of Science, Industry, and Technology, the difficulties faced by the increasing amount of waste require a “waste management approach”, which aims at production and consumption without waste or with as little waste as possible [1]. Disposal of waste without damaging the environment is important for ecological balance, human health, and the economy.

According to the Organisation for Economic Co-operation and Development (OECD), “Resource efficiency and productivity ensure that materials are used efficiently at all stages of their lifecycle (extraction, transport, manufacturing, consumption, recovery and disposal) and throughout the supply chain. Moving towards a resource efficient and circular economy is critical from both supply security and environmental perspectives and provides the basis for a sustainable and competitive economy” [2]. All the unused substances in the form of solids, liquids, and gases that are formed as a result of production and consumption during the life cycle process constitute waste. Wastes are divided into different categories in different literature in terms of source. Hazardous waste, non-hazardous industrial waste, municipal solid waste, agricultural and animal waste, medical waste, radioactive waste, construction and demolition debris, extraction and mining waste, oil and gas production waste, fossil fuel combustion waste, and sewage sludge are among the many types of waste that are produced [3].

The total waste generated by all economic activities and households in the EU in 2020 was 2135 million tons or 4815 kg per capita. In the same year, 32.2% of waste was disposed of in landfills and 39.2% was recycled [4]. In the EU, the construction sector accounted for 37.5% of the waste, followed by mining and quarrying (23.4%), waste and water services (10.8%), manufacturing (10.6%), and households (8.2%) in 2020. Among the waste produced in the EU in 2020, 95.5 million tons (5.1% of the total) were classified as hazardous waste. In 2020, the EU produced 5.1% more hazardous trash than it did in 2010. With a peak of 102.0 million tons in 2018, there has been an increase in quantity from 90.8 to 95.5 million tons. Türkiye (28.5%) and North Macedonia (28.2%) had the highest percentages of hazardous waste and total waste generation among non-EU nations. If dangerous waste is not handled and thrown away in a safe way, it poses a high risk to human health and the environment. In EU policies, especially with the EU Sustainable Development Strategy, 6th and 7th Environmental Action Plan (EAP), the importance given to resource utilization, resource efficiency, and waste has increased. The sustainable use of resources and the objective of sustainable growth of the Europe 2020 Strategy and increasing waste recycling are also addressed in the “Resource Efficient Europe document” [5].

According to Fedotkina et al. (2019), solid waste collection, processing, and recycling are shared responsibilities among all stakeholders in the ecosystem. The federal government, local governments, private citizens, companies, and newcomers, such as regional operators and eco-industrial parks, are all considered as stakeholders. The government provides other players with financial incentives, financing for infrastructure development, and regulations. Local governments are responsible for handling waste in their communities. Solid waste collection, processing, and recycling are the responsibility of businesses. The task of collecting separate waste falls on households. From a garbage tank to the range or processing facility, regional operators are in charge of overseeing all waste management practices [6].

Every nation has laws requiring waste management in place because it is so important to public health. Although towns are legally obligated to offer or organize services, their actual implementation is frequently insufficient in developing nations, primarily because of the limited financial and technical resources available to municipal administrations. In these situations, it can be useful to supplement the public sector by working with a variety of various private sector service providers, from big private firms to tiny and micro-enterprises, in order to guarantee locally relevant and reasonably priced services [7]. An effective waste management system will also contribute to sustainable economic growth with the effect of reducing dependence in sectors with a high dependence on raw materials and intermediate goods. This will ensure the protection of natural resources and the environment and protect human health.

According to Taelman et al. (2018), the creation of a life cycle thinking-based conceptual sustainability framework for waste management can assist businesses, regional and local authorities, and policy makers in identifying resource-efficient ways to improve social, environmental, and economic performance [8]. Starting with an analysis of the current waste management system is crucial. This includes determining how materials move through urban and rural areas of a city and beyond, as well as the quantity and value of streams, the stakeholders and actors involved, their links and proximity, the role of land and infrastructure, and other factors, which vary depending on the metropolitan area. Authors have analyzed the recently developed sustainability frameworks with the models they used for waste management by summarizing 22 articles proposed. Methods/tools commonly used are multi-criteria and optimization techniques, life cycle analysis, flow and value analysis methods, Life Cycle Costing and Social Life Cycle Assessment [8].

When the literature reviewing critical success factors in waste management is examined, it is seen that different criteria are considered by different authors in different industries but not prioritized by using one of the multi-criteria decision-making methods in the industrial waste management area. In addition, in other studies, it was observed that employee opinions were not included in the study and CSFs on a sectoral basis were not compared with other sectors. By filling this gap with this study, an attempt has been made to create a framework for future studies. Prioritization is important in terms of macro-action plans at the country level and micro-action and investment plans at the enterprise level.

This study pursued answers to the following research questions: i. What are CSFs’ priorities in waste management? ii. Does the priority ranking of CSFs in waste management vary according to different industries? iii. Is there a difference between the opinions of employees and environmental engineers regarding CSF rankings?

The aim of this study is to determine the main critical success factors in industrial waste management as well as the sub-factors and put forward an AHP-based prioritization methodology that will eliminate the lack of reference. Thus, decision makers will pay attention to priorities and make effective investments when making decisions on waste management with a limited budget. Furthermore, the waste management CSF priorities according to the environmental engineers from different industries were determined by the AHP method and employees’ thoughts on the same issue were prioritized through a survey.

The rest of the paper is organized as follows. In Section 2, the literature review related to the CSFs in WM is presented. Then, the methodology of the research is explained in detail along with the materials used and methods applied. AHP findings from environmental engineers, rankings of CSFs according to different industries and survey results from employees are presented in Section 3. In Section 4, our findings are compared with the literature. Section 5 provides the final conclusions.

2. Related Works

In this section, critical success factors in waste management in different industries as well as factors affecting the circular economy and green supply chain have been examined.

2.1. CSFs in General Waste Management in Circular Economy and Supply Chain

In 2013, Renwick et al. discussed the “Green Human Resources Management” approach in order to create waste management and environmental awareness in enterprises and to apply this awareness at every stage of business processes. In this work, they included the selection and recruitment factors for employees within the scope of talent development; included performance management and evaluation factors within the scope of training and development; employee motivation; critical success factors related to employee engagement, empowerment, and participation; a supportive organizational culture climate; employee engagement; and trade union tasks in environmental management, within the scope of the wage and reward system [9].

For the purpose of identifying and categorizing drivers and Critical Success Factors in the context of the circular economy (CE), a final collection of 55 articles was chosen by the authors and these CSFs were suggested for further research on CE: technological, economic and financial, institutional, strategic and external [10].

In order to contribute to a broader understanding of the early stages of the introduction of circular economy related business models inside SMEs, the authors focused on the investigation of the role of organizational learning processes and related contextual elements, which includes the identification of intra-organizational and inter-organizational learning processes that may support the sustainable evolution of business models [11]. The identification of cultural, structural, regulatory, and procedural contextual aspects at the external, supply chain, and organizational levels, as well as how those elements connect to relevant intra-organizational and inter-organizational learning processes, were the main implications of their study.

Regarding the fundamental and crucial function that green supply chain management (GSCM) plays in achieving the goal of sustainable development, Agrawal et al. (2023) analyzed the critical success factors for the manufacturing industry’s successful implementation of GSCM procedures by using AHP, TOPSIS, and DEMATEL methodologies [12]. They selected nine CSFs after their literature review and these were confirmed by 189 management experts. Reverse logistics management was found as the primary factor leading to the successful implementation of SGSCM methods, and it has been determined that high management commitment is the most significant critical success factor. Other CSFs were listed in importance order as adoption of new technology and processes, employee involvement, customer requirements, government regulations and standards, brand image building, training, sustainability, and reverse logistics management [12].

Critical success factors (CSFs) were identified, prioritized, and their relationships with one another were examined using an integrated decision-making multi-criteria decision-making methodology by the authors to implement green SCM practices in the apparel manufacturing industry [13]. Debnath et al. (2023) listed the ranking of the CSFs according to influence level: demand from buyers, economic and tax benefits, government rules and regulations, sustainable adoption of green technologies, sustainable supplier selection, high management commitment, achieving and sustaining environmental certifications, green awareness, global competition factor, availability of qualified and skilled manpower, sustainable energy management and reduction of fossil fuel usage, efficient reverse logistics management, sustainable waste management system, sustainable logistics and inventory management, supplier training and cooperation, and green sourcing and procurement [13].

Bhattacharjee et al. (2023) contributed to the literature by examining the key success factors (CSFs) of circular economy implementation in the waste electrical and electronic equipment (WEEE) sector and determining their causal links and order of importance [14]. Authors found that “Market Contenders”, “Formation of Cross-functional Teams”, “Global Standard”, “Skilled Manpower”, Financial Sustainability” and “Consumer Awareness” were the prominent CSFs in WEEE.

2.2. CSFs in Construction and Demoliton Waste

Lu and Yuan (2010) found that economic growth in China has produced large amounts of construction and demolition waste in the last 30 years, but the best way to remedy this has not yet been explored, although a better waste management system is needed. In the study, Shenzhen was chosen as the research area in the south of China, the leading city for construction and demolition waste management. After they received feedback from surveys, they listed CSFs as follows: material usage and storing system, fewer design changes, developing contributions from the project attendees, waste management life cycle, waste management regulations, recycling and reuse, an in situ waste audit system, in situ classification of waste, construction technologies, including less waste, awareness, improving traditional construction processes, environmental management systems, waste management systems, dwelling industrialization programs, research and development activities in waste management, occupational training in waste management, measurable waste management systems, considering waste management in bidding and tendering processes. As a result of the analysis of survey data with SPSS 15.0, seven critical success factors with the highest level of importance for managing construction and demolition waste were identified: (1) Waste management regulations, (2) Waste management system, (3) Awareness, (4) Low-waste construction technologies, (5) Fewer design changes, (6) Waste management research and development, and (7) Waste management vocational training [15].

Omran and Eltayed (2016) published a study to identify and prioritize critical success factors for waste management in construction projects in Khartoum, Sudan. They identified 18 critical success factors to analyze and compared previous studies. A quantitative method was used to collect the data. With the aim of the project manager, contractor and consultant, 65 surveys were sent to different companies in Khartoum city, where construction activities are intense. SPSS 20.0 was used to look at the data from 45 questionnaires, and the 10 most important success factors that came out of the analysis are listed below: material use and storage systems; better communication between project participants; in-house waste control systems; research and development in waste management; vocational training in waste management; improvement of traditional construction processes; waste management systems; waste management awareness in construction and demolition processes; waste management regulations; and waste management awareness in the bid-tender process [16].

Ding et al. (2018) reported that prior research mostly addressed the broad facets of construction waste management, including policy, the environment, the economy, society, and management issues [17]. According to Maranesi and De Giovanni (2020), the limits of the companies must be expanded under the circular environment paradigm to include supply chain (SC) partners who share the same commitment to circularity. Circular SC is defined as incorporating circular thinking into supply chain management and the surrounding industrial and ecological ecosystems, which systematically restores materials towards a zero-waste vision. To be successful, senior management and shareholders must work together to advance technological and innovative projects, forge business alliances in order to establish integrated circular supply chains, and successfully advocate for organizational and cultural reforms [18].

2.3. CSFs in Health Care and Medical Waste

Baaki et al. (2017) published a case study to identify critical success factors for medical waste management in Nigeria. The aim of their work is to identify the critical success factors of medical waste management in developing countries and to assess the recognition and implementation of these factors to inspect why medical waste management in Benue State, Nigeria, does not achieve its goals. In a study conducted to develop the National Health Waste Management Plan of Angola, it was found that environmental policies and legislation are the most important critical success factors as a result of the study, which is based on some of the critical factors required for medical waste management application. It was stated that there are special and detailed regulations regarding medical waste in accordance with international environmental rules and regulations as the second critical factor, and that the third most critical factor is infrastructure and an adequate and productive labor force within the scope of financing and investment [19].

Dixit and Dutta (2024) used structural modelling embedded a fuzzy decision-making trial to identify the most important critical success factors for adopting a circular economy in the health care industry [20]. Among 17 critical success factors, the authors found that 12 CSFs, ‘Information Visibility and Transparency’, ‘Service Provider Responsibility’, ‘Government Responsibility’, ‘Manufacturer/Corporate Responsibility’, ‘Budget Allocation’, ‘Consumer Responsibility’, ‘Training and Empowerment’, ‘Tax Incentive’, ‘Monitoring and Regulation’, ‘Publicity/Awareness’, ‘Stakeholders’ Participation’ and ‘Segregation/Collection’, are accepted in the cause group. The other five CSFs are documented under the effect group: ‘Public Ethics’, ‘Product Design’, ‘Infrastructure Design and Development’, ‘Technology Involvement’ and ‘Data Estimation’.

2.4. CSFs in Solid Waste

Jibril et al. (2012) discuss the 3Rs strategic approach to raise awareness among people who make waste in order to lower the cost of running the system and reduce the amount of solid waste, which is important for managing waste in higher education institutions in an efficient and effective way. This study classified critical success factors according to the waste management hierarchy, which include waste prevention and mitigation, recycling and reuse, waste treatment, and disposal. As a result of the study, they emphasized that the reduction, reuse and recycling of solid wastes can be achieved with the 3R strategic approach, fully implemented in higher education institutions, thus reducing costs and improving performance. They stated that traditional practices of solid waste management in higher education institutions should be replaced by integrated approaches for a cleaner environment and the efficient cost effectiveness of the whole system [21].

Jibril et al. (2013) researched the importance of awareness of 3R critical success factors in “Green Higher Education Institutions”. In this study, they also classified critical success factors in waste management according to the 3R approach, i.e., Reduce:Decrease, Reuse:Use, Recycle:Recycling. They stated that energy and water saving sub-critical success factors include using fewer packaging and packaging materials, using waste materials in new designs or selling them to other institutions for evaluation, and adding waste products or packaging products to the recycling chain. They stated that the “awareness” factor was important in determining the failure or success of the solid waste management system in higher education institutions all over the world [22].

3. Materials and Methods

In this part of the study, the research methodology is explained, with details of the materials and methods used. Findings from the worldwide literature on CSFs in waste management were combined with the regulations and literature from Türkiye, as mentioned below.

The main purpose of the waste management system is to ensure less waste production and then to recycle or compost the resulting waste into the system. The main regulation in the field of waste management is the Waste Framework Directive 2008/98/EC. The Framework Directive defines the hierarchy of waste management [23]. According to the waste management hierarchy, waste management strategies should focus primarily on the prevention of waste generation at the source. Where this is not possible, waste materials must be reused and, if not, recycled. Waste materials that cannot be recycled should be used for recovery (e.g., energy recovery). The safe disposal of waste in incineration plants or landfills is the last option in the waste management hierarchy. Industrial wastes, in general terms, are wastes arising from industrial activities. In recent years, interest in industrial waste has become an important issue due to the growing population and consumption of industrial products. Key factors are: i. to reduce the amount of waste that needs to be reduced and the use of harmful substances during manufacturing processes; ii. to internalize environmental thinking in the use of materials by using recycled products and creating markets.

The Turkish National Recycling Strategy Document and Action Plan of the Ministry of Science, Industry, and Technology for the period 2014–2017 explains why a waste management approach is needed [24]. After performing a SWOT analysis related to the recycling area, the problem areas shown in

Table 1. Türkiye’s National Recycling Strategy Document, Action Plan Priority Problem Areas [24].

Weak Points	Problem Areas
Lack of awareness about the economic value of waste. Lack of awareness and environmental awareness about recycling from the public and industrialists. For industrialists, environmental issues are secondary. Insufficient training on recycling. Lack of cooperation between public–local administrations–NGOs in awareness-raising activities.	Level of Consciousness and Awareness.
Waste in economic value cannot be collected separately from other wastes. Existing legislation does not contain the features needed to meet needs and demands. The financial sector is adversely affected by the harmonization of EU legislation. Ineffective implementation of legislation. The standard of the recovered secondary product is low.	Administrative and Legal Arrangements
Lack of common collection points; waste cannot be collected separately at source. Lack of administrative and technical capacity of local governments. Lack of special recycling facilities for some products and waste and small number of recycling facilities.	Infrastructure
Recycling issues are an additional financial burden on industrialists. The SCT (Special Consumption Tax) problem in the sale of recycling products. Lack of financing model in waste management. Lack of incentive and guidance system.	Financing and Support
The presence of registration and unlicensed collectors. Inadequate legislative sanctions and non-implementation of these sanctions. Lack of elements enabling recycling. Lack of experienced staff in implementing legislation. Lack of reliable and up-to-date statistics. Existence of legal practices which are not prepared in accordance with the realities and infrastructure of the country. Unclear distribution of tasks between institutions and lack of coordination.	Application

were highlighted in the plan, which guided us in determining critical success factors in our study.

Özbay (2006) included the subject of solid waste management and related general objectives in his book and summarized the points to be considered in solid waste management as follows:

• Ensuring the circulation of waste in society,
• Reducing raw material consumption,
• Reducing the use of solid waste,
• Reusing materials,
• Seeking ways to regain materials,
• Providing energy savings,
• Carrying out solid waste management [25].

Büyüközkan and Vardaloğlu (2008) published a literature study titled Green Supply Chain Management. In this study, they discussed green managerial approaches that should exist within enterprises. From the procurement of raw materials to after-sales services, they examined the environmentally-friendly approach that must exist in every process and in the enterprises dealing with production and revealed the key success factors that should be included in all these processes. According to Büyüközkan and Vardaloğlu, the low concentration of hazardous, harmful and toxic substances is one of the key success factors in product and by-product design. The amount of energy and raw material used is another key success factor and, if a product is produced in processes that reduce energy and raw material consumption in an enterprise, this means that green production activities take place in that supply chain. Another key success factor is the use of recyclable, reusable and reprocessable materials in product design [26].

3.1. Materials

During the study, new factors were added to the CSFs in the literature. Figure 1 shows the main and sub-criteria that were put together after reviewing the literature.

For the environmental engineers’ opinions in obtaining AHP data, sectors such as iron–steel, automotive and food, which are the main locomotive sectors for Türkiye, were selected, and AHP evaluations were carried out with five expert environmental engineers working in these sectors. The profile details of environmental engineers are given in

Table 2. Profile details of environmental engineers.

Expert	Industry	Position	Educational	Experience	Age Group	Gender
No			Level	(Years)
1	Automotive industry A	Middle manager	MSc and PhD	19 years	40–54	Female
2	Automotive industry B	Middle manager	BSc	10 years	30–39	Male
3	Steel Industry A	Senior engineer	MSc and PhD	9 years	30–39	Male
4	Steel Industry B	Top manager	MSc and PhD	23 years	40–54	Female
5	Food Industry A	Senior engineer	BSc	21 years	40–54	Male

. In addition, the survey was distributed to 2000 randomly selected employees via social media and e-mailing. With the survey prepared using Google Forms, a total of 101 valid responses were received from the participants. Microsoft Office Excel 2016 version was used to collect and organize the data.

3.2. Method

3.2.1. Analytic Hierarchy Process (AHP)

The AHP method, developed by Saaty in 1977, is a method used to solve complex decision problems involving multiple criteria [27]. AHP allows decision makers to model complex decision problems in a hierarchical structure that illustrates the relationship between the main objective, criteria, sub-criteria, and alternatives regarding the problem. AHP, which is a method of logically combining knowledge, experience, and individual thoughts, is used effectively in many decision problems.

In AHP, the problem that is the subject of the decision-making is organized in a hierarchical structure by being separated into its components. Binary comparisons are the basic building blocks of AHP. When making binary comparisons between the criteria, the basic comparison scale contains values from 1 to 9 [27].

The steps to achieving benchmark weights with AHP are as follows. 1: A comparison matrix is created in which binary comparisons are made. In the comparison, the scale developed by Saaty is used. 2: The generated comparison matrix is standardized. To do this, the column totals are taken and each value is divided by its column total. This results in a standardized matrix. 3: The weights are calculated by averaging the line. 4: After obtaining the weights, check the consistency of the comparison matrix. If the comparison matrix is not consistent, the resulting weights cannot be used. In AHP applications, the consistency ratio is less than 0.1, which means that the application is consistent. If this value is exceeded, the judgments made should be reviewed.

3.2.2. Critical Success Factors (CSFs)

This approach was developed by Bullen and Rockart (1981) at the Massachusetts Institute of Technology and aims to accurately identify information needs and meet organizational objectives. In CSF, the goal is to achieve the objectives by concentrating on the key areas that ensure that the necessary part of the information is decomposed and that the success factors and the process are carried implemented correctly. In short, Critical Success Factors are the criteria that determine whether a good system has been developed or not and ensure the success of the business process when it is achieved. A limited number of elements, conditions, or variables that have a direct impact on the effectiveness, efficiency, and validity of an organization, program, or project can also be defined as a CSF. According to Bullen and Rockart, CSFs contain four to six business factors on average. This is also prepared in a hierarchical structure on the basis of industry, organization, sub-organization, and related functions. CSFs arise from the structure of the industry, the competitive strategy, and the place of the organization in the industry; environmental factors (e.g., economic situation, political situation, etc.); temporary factors; the role of the manager; and the worldview. CSFs are therefore time-dependent. Although appropriate factors are identified, events may change the criticality of these factors. Therefore, these factors should be reviewed from time to time. CSFs relate to the daily information needs of decision-makers. To achieve this, the following must be known: the determination of the key areas that indicate whether the management has achieved its purpose and the performance criteria in these areas, identification of problems in the relevant business function, and determining what main decisions have to be made to obtain this information. [28].

3.3. Methodology

As seen in Figure 2, first, the critical success factors were determined by reviewing the literature. The main objective in the formation of a hierarchical structure is the selection of critical success factors in industrial waste management. In this study, there are 4 main criteria and 23 sub-criteria: (1) National\Local waste management strategies and policies, (2) Enterprise waste management strategies and policies, (3) Recovery management and (4) Awareness raising. The hierarchical model for the problem is given in Figure 1. After preparing surveys for employees and AHP scales for experts, surveys were sent to a randomly selected 2000 employees. At the fourth phase, the AHP method was used to prioritize the critical success factors, and the opinions of five environmental engineers from the automotive (two), steel (two), and food (one) industries were collected by face-to-face interviews. To compare experts and employees thoughts on waste management CSFs, the arithmetical average of the AHP scores given by five environmental engineers was found and the priority values of the main and sub-criteria were determined. The survey data were analyzed with IBM SPSS Statistics version 25.

4. Results

4.1. AHP Findings from Environmental Engineers

In this part of the study, binary comparison matrices are included. Firstly, the pairing comparison matrices are established between the main criteria, and the importance levels between the main criteria are determined (See

Table 3. Comparison of Main Criteria Matrix and Importance Levels.

Critical Success Factor	Legal Regulations	Business Policies	Recycling	Education and Awareness	Importance Level
Legal Regulations	1.00	3.00	5.00	5.00	0.5280
Business Policies	0.33	1.00	4.00	5.00	0.2956
Recycling	0.20	0.25	1.00	2.00	0.1052
Education and Awareness	0.20	0.20	0.50	1.00	0.0712

Consistency Ratio (CR) = 0.0634.

).

A consistency ratio (0.0634) of less than 0.1 indicates the consistency of the data. The legal regulation criterion was that with the highest importance. This is followed by the criteria of business policies, recycling, and education and awareness. After finding the importance levels of the main criteria, the comparison matrices of the sub-criteria of each main criterion were examined and the significance of the sub-criteria was found.

Appendix A shows the comparison matrix of sub-critical success factors for “Legal Regulations”, which is one of the main criteria. In the evaluation made according to the multi-criteria decision-making technique, the criterion of “Effective implementation of legislation” was found to be the most important sub-criterion of “Legal Regulations”, with 42.61%. Appendix B shows the comparison matrix for the sub-critical success factors of the enterprise waste management strategies and policies. As a result of the comparison, the sub-criterion of “Adequate budget and resource allocation for waste management” ranks first, with 27.55%. “Having green design principles in product design” takes the second place, with 25.76%. Appendix C contains the comparison matrix for the sub-critical success factor of “recycling management”. “Use of environmentally friendly materials with less hazardous properties in production” was found to be the most important sub-criterion, with 50%. Appendix D contains the comparison matrix for the subcritical success factors of “education and awareness”. “Providing training to create awareness of prevention and reduction of waste” is the most important sub-criterion of this main criterion selected by environmental engineers. The values obtained as a result of comparison matrices between sub-criteria were obtained by multiplying the importance levels of the main criteria and weight values in Appendix E. The values found as a result of the comparison matrices between sub-criteria were multiplied by the importance levels of the main criteria to obtain the weight values in Appendix F. After pairwise comparison of the sub-criteria, each critical success factor was evaluated according to all sub-criteria and the data in

Table 4. The Importance Values of the Sub-Criteria as a result of the Five Expert Engineers.

	Symbol	Sub-Criteria (SC)	Legal Regulations	Business Policies	Recycling	Awareness and Education
0.0389	SC11	To be able to meet the legislative demands and needs	0.0148	0.0160	0.0055	0.0026
0.2250	SC12	Effective implementation of legislation	0.1078	0.0707	0.0313	0.0152
0.0927	SC13	The availability of adequately equipped personnel in the implementation of the legislation	0.0419	0.0323	0.0118	0.0068
0.1251	SC14	Effective implementation of sanctions and penalties for waste management	0.0546	0.0443	0.0162	0.0100
0.0462	SC15	Adequate standards for the recycled secondary product	0.0186	0.0174	0.0058	0.0044
0.0414	SC21	Material handling and storage systems have a zero waste principle.	0.0192	0.0137	0.0050	0.0035
0.0237	SC22	Reduce the amount of packaging used in products.	0.0106	0.0079	0.0033	0.0019
0.0163	SC23	Attaching importance to electronic Communication.	0.0074	0.0057	0.0021	0.0012
0.0761	SC24	To have green design principles in product design and fewer design changes.	0.0327	0.0281	0.0093	0.0060
0.0091	SC25	Energy saving.	0.0044	0.0028	0.0011	0.0007
0.0815	SC26	Adequate budget and resource allocation for waste management.	0.0380	0.0256	0.0113	0.0065
0.0359	SC27	Having an on-site waste control system.	0.0183	0.0116	0.0037	0.0022
0.0115	SC28	Rewarding the suggestions of employees in environmental management	0.0057	0.0035	0.0015	0.0009
0.0526	SC31	Use of environmentally friendly materials with less dangerous properties in production	0.0273	0.0155	0.0067	0.0032
0.0170	SC32	Reduction of the use of non- processed raw materials	0.0077	0.0064	0.0017	0.0011
0.0199	SC33	Ensuring the reuse of waste as raw materials	0.0076	0.0077	0.0029	0.0017
0.0058	SC34	Ensuring the recovery of waste	0.0023	0.0023	0.0008	0.0004
0.0098	SC35	Ensuring the use of classified trash cans	0.0042	0.0037	0.0012	0.0007
0.0314	SC41	Providing training to create awareness of prevention and reduction of waste.	0.0148	0.0101	0.0040	0.0025
0.0174	SC42	Providing training for waste recovery awareness.	0.0082	0.0061	0.0020	0.0012
0.0104	SC43	Organization of reuse project competitions.	0.0045	0.0038	0.0013	0.0008
0.0086	SC44	Supporting the behavior of managers in order to ensure employee participation in environmental management.	0.0040	0.0030	0.0010	0.0006
0.0034	SC45	To include environmental substances in job descriptions.	0.0015	0.0013	0.0004	0.0003
	Total		0.4561	0.3394	0.1300	0.0745

were obtained.

As shown in Table 4, giving the evaluation of the sub-criteria of the critical success factors, the importance of the main criteria and rankings were obtained.

As seen in

Table 5. Ranking of Critical Success Factors in Industrial Waste Management.

Priority Ranking	Main Criteria	Importance Level
1	National\Local waste management strategies and policies	0.4561
2	Waste management strategies and policies	0.3394
3	Recycling management	0.1300
4	Awareness raising and education	0.0745
Total		1.0000

, the main critical success factors in industrial waste management according to importance level are listed as follows: national and local waste management, enterprise waste management strategies and policies, recycling management, and awareness raising and education.

According to the findings, as seen in Table 5, the “National/Local waste management strategies and policies” factor was determined as the most important Critical Success Factor, with a significance level of 0.4561. This is followed by “waste management policy of the enterprises”, with a significance level of 0.3394.

4.2. Rankings of CSFs According to Industry

The details of the main CSFs according to the industry are listed in

Table 6. CSF Ranking by Industry.

		Importance Level
CSF	Industry	Automotive	Iron and Steel	Food	General
Legal Regulations		0.1084	0.6355	0.2989	0.4561
Business Policies		0.3904	0.2023	0.4822	0.3394
Recycling		0.3244	0.1033	0.1389	0.1300
Awareness and education		0.1769	0.0589	0.0800	0.0745
Total		1.0000	1.0000	1.0000	1.0000

. The scores given by each expert were also analyzed within their own industry, and the data in Table 6 were obtained. As a result of the scores given by two experts from the automotive industry, it was seen that the most important factor for this sector were the waste management strategies and business policies of the enterprise. For the iron and steel industry, two expert opinions discerned that the most important critical success factors are national/local waste management strategies and policies (legal regulations). An expert opinion in the food industry pointed that the waste management strategies and policies of the business constitute the most important critical success factor, similar to the automotive industry.

To find out the differences in rankings of sub-critical factors more accurately, Pareto diagrams are used. While the x axis shows the 23 sub criteria, the y axis discerns the importance level of each factor in Pareto diagrams. When individual values are shown in descending order by bars in Pareto diagrams, the curved line is used to show the cumulative total. People should concentrate on the “vital few” 80% CSFs and make sure that the remaining 20% (many useful) CSFs are not completely ignored. In Figure 3, it is seen that nine factors (SC12, SC14, SC13, SC26, SC24, SC31, SC15, SC21, SC11) for general evaluations can be viewed as the most important sub-factors with a total cumulative weight of 77.95% of the “vital few” factors. ”Effective implementation of legislation” and “Effective implementation of sanctions and penalties for waste management” are found to be the two most important sub-success factors.

Based on Pareto analysis, it can be seen in Figure 4 that the first 10 sub-criteria represent 77.69 of all identified sub-success factors. These elements are the “vital few” factors that affect waste management success for the automotive industry. “Material handling and storage systems have zero waste principle (SC21)” and “Use of environmentally friendly materials with less dangerous properties in production (SC31)” sub-factors are found to be the most important factors, with a total cumulative weight of 26.5%.

Based on the analysis of Figure 5, the first important factor in the iron and steel industry is “Effective implementation of legislation (SC12)”, with 32.76% of occurrences. Then follows “Effective implementation of sanctions and penalties for waste management (SC14)”, with an occurrence rate of 14.69%. The first eight sub-criteria represent 79.61% of all the identified sub success factors as “vital few” factors, and the remaining 15 sub-criteria are “useful many” CSFs for successful implementation of waste management systems in the iron and steel industry.

Based on the analysis of Figure 6, the three most important factors in the food industry are “Adequate budget and resource allocation for waste management (SC26)”, “Effective implementation of legislation (SC12)”, and “to have green design principles in product design and fewer design changes (SC24)”. The first 10 sub-criteria as “vital few” factors represent 78.00% of all sub-success factors, while the remaining 13 sub-criteria are “useful many” CSFs for successful implementation of waste management systems in the food industry.

4.3. Survey Findings from Employees

Surveys were sent via email and social media to the randomly chosen small and large businesses in Türkiye, and 101 valid questionnaires were filled out and sent back by employees. The split-half reliability and internal consistency of the questionnaire were evaluated. The split-half reliability was also strong, with a Spearman–Brown coefficient of 0.857 and a Guttman split-half coefficient of 0.853. Cronbach’s alpha for the 27 questionnaire items was 0.879, indicating good internal consistency reliability. These findings show that the questionnaire has a high degree of reliability. The questionnaire exhibits good internal consistency and split-half reliability, as seen by the high split-half coefficient and Cronbach’s alpha values.

According to the descriptive statistics of the survey, 44.6% of respondents have a Masters’ degree and 38.4% are managers, as seen in

Table 7. Descriptive Statistics of Survey Respondents.

Variables	Groups	n	%
Gender	Female	49	48.5
	Male	52	51.5
Age Group	20–39	80	79.2
	40–54	21	20.8
Education level	Associate Degree	3	2.9
	BA. BS.	53	52.5
	MS. MBA	45	44.6
Industry	Automotive	27	26.7
	Iron and Steel	17	16.8
	Food	15	14.9
	Energy	10	9.9
	Chemical, Petroleum, Rubber and Plastic	9	8.9
	Woodworking, Paper and Paper Products	8	7.9
	Glass, Cement and Soil	3	3.0
	Other	12	11.9
Position	Business Owner/Partner	1	0.9
	Senior Manager	6	5.9
	Mid-Level Manager	32	31.6
	White Collar Employee	62	61.3
Waste Management Training Status	I have never received	18	17.8
	I received once	58	57.5
	I receive training once a year.	22	21.8
	I receive training more than twice every year	3	2.9
Waste Management applied in their company	Yes	98	97.1
	No	3	2.9
Satisfaction with waste management service	Yes	70	69.3
	No	31	30.7
The most important problem in waste man.	Lack of my knowledge	19	18.8
	The intensity of my work	10	9.9
	I don’t find the subject important.	1	0.9
	Sufficient budget and resources are not allocated.	33	32.7
	The absence of any control system	38	37.6
Satisfaction with the waste collection method	Yes	71	70.3
	No	19	18.8
	I don’t know\I have no idea	11	10.9
Throwing waste in segregated bins	Lack of knowledge	2	2.0
	The intensity of my work	1	1.0
	I don’t find the subject important.	0	0
	Insufficient number of segregated buckets	22	21.8
	Only in limited areas in their segregated buckets	33	32.7
	The absence of any control system in this regard	22	21.8
	I don’t have any problems, I parse it every time	21	20.8

. A total of 58.4% of survey respondents work in the same sectors (auto, steel and food), where five experts were interviewed face-to-face for AHP. While 21.8% receive waste management training once a year, 17.8 percent of them have not taken any WM training before.

According to

Table 8. Importance Level Distribution of the Main Criteria According to Survey Findings.

Main Criteria		Importance Score					Mean	Priority
	n	1	2	3	4	5
Legal Regulations	101	1	6	27	35	32	26.27	2
Business Policies	101	0	2	16	48	35	27.93	1
Recycling	101	8	27	28	23	15	20.87	4
Education and Awareness	101	0	10	25	32	34	26.20	3

, employees think that the most important main critical success factor is business policy. While legal regulations rate as priority number 2, education and awareness ranks as priority number 3.

As seen in

Table 9. Importance Level Distribution of the Sub-Criteria According to Survey Findings.

Main Criteria	Sub-Criteria	Importance Score *					Mean	Priority
		1	2	3	4	5
Legal Regulations	To be able to meet the legislative demands and needs	0	9	31	35	26	25.40	10
	Effective implementation of legislation	1	11	24	35	30	25.67	8
	The availability of adequately equipped personnel in the implementation of the legislation	1	24	28	33	15	22.67	13
	Effective implementation of sanctions and penalties for waste management (WM)	2	10	26	29	34	25.73	5
	Adequate standards for the recycled secondary product	9	30	40	20	2	18.60	21
Business Policies	Material handling and storage systems have a zero waste principle.	2	15	43	29	12	22.47	14
	Reduce the amount of packaging used in products.	1	15	39	34	12	22.93	12
	Attaching importance to electronic communication.	2	23	34	34	8	21.73	16
	Having green design principle in product design and fewer design changes.	9	26	30	28	8	20.20	19
	Energy saving.	0	5	36	33	27	25.67	6
	Adequate budget and resource allocation for waste management.	0	2	32	36	31	26.60	2
	Having an on-site waste control system.	0	5	23	46	27	26.53	3
	Rewarding the suggestions of employees in environmental man.	13	33	26	23	6	18.60	22
Recycling	Use of environmentally friendly materials with less dangerous properties in production	4	25	39	23	10	20.87	18
	Reduction of the use of non- processed raw materials	9	25	37	21	9	19.93	20
	Ensuring the reuse of waste as raw materials	1	29	29	25	17	22.07	15
	Ensuring the recovery of waste	3	8	46	28	16	23.27	11
	Ensuring the use of classified trash cans	0	6	28	46	21	25.67	7
Education and Awareness	Providing training to create awareness of prevention and reduction of waste.	1	2	40	27	31	25.87	4
	Providing training for waste recovery awareness.	0	3	28	37	33	26.87	1
	Organization of reuse project competitions.	22	38	19	18	4	16.47	23
	Supporting the behavior of managers in order to ensure employee participation in environmental management.	1	7	30	38	25	25.47	9
	To include environmental substances in job descriptions.	14	10	32	32	13	21.53	17

* 1: very unimportant, 5: very important.

, employees select the top five most important sub-critical success factors as providing training for waste recovery awareness, adequate budget and resource allocation for waste management, having an on-site waste control system, providing training to create awareness of prevention and reduction of waste, and effective implementation of sanctions.

In Figure 7, employees rankings of 23 sub-critical factors according to different industries are shown and compared in a radar graph.

5. Discussion

Baaki et al. published a case study to identify critical success factors in medical waste management in Nigeria. In this study, it was revealed that environmental policies and regulations are the most important critical success factor, and the second critical factor consists of specific and detailed regulations on medical waste [19].

In their study aiming to define critical success factors for construction and demolition waste management in China, Lu and Yuan stated that (i) waste management regulations and (ii) waste management systems are the two most important critical success factors [15].

In our study, (i) National–Local waste management strategies and policies and (ii) waste management strategies and policies of the enterprise were the most important critical success factors. The results are in agreement with the two studies mentioned above.

In a literature study titled Green Supply Chain Management, the authors discussed the green managerial approaches that should be adopted in businesses. As a result of the study, they stated that the strategy and policies of the enterprise are the most important critical success factors. The results were found to be compatible with our study. The reason why recycling management is ranked lower in our study is thought to be due to the fact that our study focused on the whole enterprise, while Büyüközkan and Vardaloğlu’s study focused on the supply chain management sub-unit [26].

In

Table 10. Comparison of Research Findings and the Literature.

	Literature
CSF	Baaki [19]	Omran and Eltayed [16]	Jibril J. et al. [21]	Renwick et al. [9]	Evli [29]	Lu ve Yuan [15]	Büyüközkan and Vardaloğlu [26]	Özbay [25]	Literature Comparison
Legal Regulations	X				X	X			Agree
Business Policies	X	X				X	X		Agree
Recycling							X	X	Disagree
Education and Awareness			X	X					Disagree

. the comparison of our research findings and the literature is discerned.

Yeh et al. (2020) mention that increased relationship trust and a greater alignment between stakeholder environmental awareness and company awareness can foster positive communication and improve the reputation of firms [30]. According to Menzie and Freshman (1997), scientists, policy makers and the public should be educated about the ecological risk assessment process and how important it is to make decisions. Likewise, with this tool and philosophy, managers in the industry should give priority to the enterprise’s “waste management strategies and policies”, from material use to warehouse management; from compliance with the green design principle in product design to fewer design changes to products; from allocation of an adequate budget for waste management to rewarding those who propose environmental management [31]. There is evidence to suggest that willingness to participate in waste management is significantly correlated with general understanding about waste management [32].

6. Conclusions and Future Studies

6.1. Conclusions

In this study, critical success factors in industrial waste management are examined and prioritized by utilizing AHP and expert opinion. Industrial waste management on a sectorial basis has been addressed in the literature, and CSF prioritization has not been found via multiple criteria decision-making techniques before. In this study, the most important critical success factors in industrial waste management, sub-factors, and importance percentages of each CSF were found and valuable contributions were made to the literature. The main objective in the formation of a hierarchical structure is the selection of a critical success factor in industrial waste management. In this study, there are four main criteria and 23 sub-criteria: (1) National–Local waste management strategies and policies; (2) Enterprise waste management strategies and policies; (3) Recovery management; and (4) Awareness raising. As a result of the AHP analysis, “National/Local waste management strategies and policies” was determined as the most important critical success factor with an importance level of 0.4561. This is followed by “Business Policies” with a significance level of 0.3394. As a result of the analyses, “Recovery management,” with a significance level of 0.1300, was the third, and “Awareness raising,” with an importance level of 0.0745, was the fourth critical success factor

When we compare the survey results and environmental engineers’ opinions on a sectoral basis, we see that they are in agreement with each other. When we look at the expert opinions and survey results in the automotive industry, they state that the waste management strategies and policies of the business are the most important success factor. In this case, we can say that the most important critical success factor for the automotive industry is the company’s strategies and policies.

Likewise, for the food sector, both the AHP results based on expert opinion and the survey results filled out by employees showed parallelism and, as a result of both analyses, the waste management strategies and policies of the enterprise were the most important critical success factor.

When we look at the iron and steel sector, expert opinion has stated that national/local strategies and policies are the most important success factor and, as a result of the survey, it has been seen that national/local waste management strategies and policies and waste management strategies and policies of the enterprise are of equal importance. The fact that the second success factor in the iron and steel sector, according to expert opinion, consists of the waste management strategies and policies of the enterprise shows us that the expert opinion and the opinions of employees in the sector are parallel.

Observation of differences in sectoral success factors may depend on whether the legal regulations of the relevant sector are defined or whether the defined legislation can meet the demand and need, the dynamics within the sector itself, production processes, waste types and sources.

According to Menzie and Freshman (1997), scientists, policy makers, and the public should be educated about the ecological risk assessment process and how important it is in making decisions. Likewise, with this tool and philosophy, managers in the industry should give priority to the enterprise’s “waste management strategies and policies,” from material use to warehouse management, compliance with the green design principle in product design, fewer design changes to products, allocation of an adequate budget for waste management, and rewarding those who propose environmental management [31].

6.2. Future Study Suggestions and Recommendations

The study was conducted to determine the critical success factors in the management of industrial waste. However, there are not only industrial wastes but also medical wastes, hazardous wastes, urban wastes, institutional wastes, agricultural wastes, and special wastes. Work in these areas will benefit both in terms of approaching waste management as a whole and in creating data when preparing national waste management plans. In this study, only environmental engineers’ opinions in the automotive, steel and food industries have been taken.

One of the limitations of this study is our sample size, as the time of data collection coincided with the Covid pandemic. In future, similar studies can be conducted by increasing the sample size and collecting larger data sets through face-to-face interviews and obtaining the opinions of both environmental engineers and certified experts from different sectors. Since the study did not cover some industries, such as service, mining and construction industries, using the AHP model proposed by this study in Figure 1 and the methodology recommended in Figure 2, different industry experts and employees can prioritize CSFs by using multi criteria decision methods. Thus, priorities can be found according to different industries, and differences and similarities can be evaluated to determine the main factors affecting the WM system.