In recent years, industrial symbiosis (IS) has been the focus of managing industrial parks (IPs). The main reasons for this are the high potential for reducing production expenses and improving system sustainability. IS represents a concept that involves different companies to collaborate and share resources to maximize the use of the available resources from all participants (internally) before being supplied from outside of IPs [1].

IS systems create sustainable and mutually beneficial relationships between industries. This results in increased efficiency and reduced waste generation. IS involves identifying and using one company's waste products as resources for other companies. Moreover, IS supports sustainable development by adopting circular economy principles. It minimizes the dependence on primary resources. Furthermore, it stimulates economic growth due to cost savings and better competitiveness.

IS implementation supports waste exchange programs and encourages companies to cooperate better with each other. That makes a closed-loop system where resources are continuously repurposed and recycled [2]. These closed-loop systems positively impact the environment. They reduce the carbon footprint and provide economic benefits. IS encourages sharing innovation and knowledge among other resources. These result in novel solutions and processes, improving the overall efficiency and sustainability of industrial ecosystems.

The main idea of IS is not limited to the physical exchange of raw materials. It also supports sharing infrastructure such as energy and water utilities, as well as implementing environmentally friendly practices and technologies. These strengthen symbiotic relationships between companies. Moreover, IS can be taken as a good model for sustainable industrial development. Furthermore, these can attract investments and promote a positive reputation within the industry and local community [3]. This approach maximizes the economic and environmental benefits of all its participants [4]. The concept of IS imitates natural ecosystems, where the waste of some organisms is used as feeding resources for other organisms [5]. Material flow analysis (component analysis) can be used to analyze these processes and support the creation of eco-industrial parks (EIP) or regional IS.

Business networks of interconnection employ several mechanisms, which include recycling waste, remanufacturing, and the transformation of by-products or waste into valuable resources for other industries [6]. It promotes the concept of “waste as a resource”. Factors such as the complex nature of logistics, disparate industry objectives, and limits on the recycling and remanufacturing of waste become risks in investments. However, detailed planning, collective efforts, and supportive policies minimize these obstacles [5].

Successfully realized ISs are the result of using effective methodologies for their design. The approach that is used depends on the priorities of projects. Implementing ISs typically involves existing production processes and companies. It is rare to establish new IPs. That is because of the significant investment costs. Therefore, they can be either retrofit designs or completely new designs. Retrofit designs update the current system with additional equipment to improve process efficiency. On the other hand, new designs involve developing a completely new system. Another important factor for the design of IS systems is the use of “total site” or “partial” improvements. It is important to understand the process of “total site integration”. That refers to the complete integration of systems between all interested parties. If improvements are made only on one site or a few parts of the system within a single company, this is considered partial integration.

The literature reported the following methodologies for the design of ISs: Material and Energy Flow Analysis [7], Resource Mapping and Matching [8], Industrial Ecology Tools [9], Stakeholder Engagement and Collaboration tools [10], and Pinch technology integration [11]. Unfortunately, the implementation of Pinch technology for the design and partial or total optimization of IPs in the form of IS is not widely adopted. This can be a result of many different factors. The objective of this study is the identification of the potential of Pinch technology in fostering IS within IPs, compared to other used methodologies. Moreover, it aims to detect obstacles and barriers to that condition.

The main question is why Pinch technology is not widely accepted in the design of ISs, what are the differences between currently used methodologies and Pinch technology, and what the benefits in design ISs with Pinch technology are. Furthermore, it should answer how Pinch technology can solve many technical and economic barriers to establishing IS. Besides, there are issues that Pinch integration cannot solve. Moreover, this work suggests a new approach that uses a combination of different Pinch technology types for the whole system integration.

Lawal et al. [11] made a literature review of tools that are useful for designing ISs and EIPs based on publishers and publishing years. That review mentions all possible tools at the time of its publication. It is completely different than this one in terms of aims and objectives. It summarized IS tools and showed optimal integration possibilities. Furthermore, it omits some tools.

This paper gives some basic characteristics of different types of IPs. It describes methodologies that are actively used in the design of ISs. Review different Pinch technologies and give the main possibilities in using them for IS, with their gaps compared to the other previously described methodologies.

This review paper is based on information from peer-reviewed published literature in ScienceDirect, Scopus, Springer, and Google Scholar databases. It uses literature published in the last 10 years. The primary search for literature is made for “industrial symbiosis” (Figure 1). From that literature, sources are filtered to include those that contain a methodology used for the design of IS (“Industrial symbiosis design methodology”). Literature that describes any methodology is selected for further consideration. It is selected by the methodology that is used for design as separate filters (“MILP”, “ABM”, “MEFA”, “LCA”, “network analysis”, “emergy analysis”, and “exergy analysis”). On the other hand, Pinch technology literature is searched separately. The first filter selects sources that include known Pinch technology methodologies (Figure 1). The next filter of sources is related to containing information that describes the Pinch technology used for the design of IS, and IS case studies. This literature search includes the main principles used in different types of Pinch technology. This is used for further finding benefits and issues related to the design of ISs. Based on this information, a comparison is made between methodologies, their issues, and information about experience in real case studies for IS design. It must be mentioned that many of the finally selected sources overlap in filter criteria (mentioning a few methodologies in the same, including Pinch technology). Some sources after the main filtration are not taken into consideration due to the fact that they did not contain relevant information for this review paper.

IPs are specialized areas only for industrial activities. They are typically located outside of urban areas to minimize environmental and social impact. IPs are categorized by the types of industries located inside them, such as manufacturing, processing, or research & development. The organizational system of IPs can be privately owned & operated, or government-managed facilities. One of the main considerations of IPs is the minimization of ecological footprints and the promotion of environmentally friendly practices. Here are included initiatives for minimizing energy consumption, effective waste management, and emission reductions. Therefore, IPs often include green infrastructure and sustainable design principles. IPs can take the form of technological parks, EIPs, Positive Energy Industrial Parks (PEIP), special economic zones, and free-trade zones.

(1) Technological parks are areas dedicated to research and development in specific scientific fields such as biotechnology or information technology [12]. Their primary task is to facilitate the exchange of ideas, resources, equipment, and individuals. Furthermore, the credibility of these parks ensures access to reliable resources and establishes connections with domestic and international business networks [13].

(2) EIPs and PEIPs create a closed-loop system by integrating multiple industries and utilizing waste by-products as raw materials [14]. EIP consists of a group of manufacturing and service businesses that work together to improve their environmental, economic, and social performance. The collaboration in the management of environmental and resource issues involves green design for infrastructure and plants of the park (both new and retrofitted), cleaner production and pollution prevention, energy efficiency, and cooperation between companies. EIP attempts to achieve positive impacts on neighboring communities with its own development [15]. The development of EIPs through the implementation of IS in IPs has become a standard practice [16]. According to Ernest A. Lowe [15], EIPs must have: 1. a multitude of exchanges of by-products or networks of exchanges; 2. numerous recycling business clusters; 3. a group of environmental technology companies; 4. a group of companies that manufacture environmentally friendly products; 5. an IP designed around a specific renewable source, such as solar energy; 6. a park that features environmentally friendly infrastructure or construction; 7. a mixed-use development that incorporates industrial, commercial, and residential components.

EIPs might have a higher development cost than traditional parks. That depends on the design choices made for a certain project [15]. The design of processes, site preparation, infrastructure features, construction methods, and building design elements may result in additional expenses. IS, on the other hand, refers to the collaboration and exchange of resources, materials, and by-products among industries within an IP or geographical area. PEIPs are a specific type of IP that focuses on promoting clean and renewable energy technologies, reducing carbon emissions, and achieving sustainability goals [17,18].

Collaboration may be a challenge when an EIP consists of companies from diverse countries and cultures. The emerging sustainable economy presents several clusters that focus on significant environmental and energy industries. These clusters include Agro-EIPs, Resource Recovery Parks, Renewable Energy EIPs, and Green Petrochemical Parks.

(3) Special economic zones [19] are areas where they implement specific economic regulations to attract foreign investment and stimulate trade. These zones often require significant investment from the government. In some cases, the government may choose to manage an EIP model.

(4) Free-trade zones are places where goods can be imported, stored, manufactured, and exported without being subject to customs duties or taxes [20].

The components and infrastructure of IS can be determined by waste and material exchange infrastructure, management and service infrastructure, technology and energy components, and regulatory and standard requirements. The core requirements include exchange systems for material and energy resources (within the park and with external partners, cascade water supply systems, integrated wastewater treatment facilities for park residents, and shared utilities, including energy, water, electricity, and heat distribution systems and joint operation facilities [water treatment and gas cleaning equipment] [21]. The waste and material exchange infrastructure has waste and by-product exchanges that enable resource conservation [22], facilities for reusing waste from one industrial process as a utility for another, either in raw form or via regeneration facilities [23], and industrial recycling systems with supply chain infrastructure that allows firms to participate in material recovery [24].

The management and service infrastructure have common management systems for material and energy resources through identified focal points or anchor residents; shared services for fire safety, transportation and other supplementary activities; and infrastructure for administrative, transport, waste management, energy and water supply systems [21]. Technology and energy components support the use of renewables, water optimization, and recovery, as well as symbiotic systems for recovering waste and material flow [25]. Regulations and standards are required for ISO management systems; land allocation for greenery, traffic works, and public utilities conforming to national construction standards; minimum number of enterprises required to participate in IS; and arrangements that facilitate symbiosis through strategic positioning and technical possibilities [24]. Based on these, the following barriers can be determined and categorized into seven dimensions: social, economic, policy, management, technological, geographical dimensions, and intermediates [26].

Economic barrier-A key economic barrier is the lack of a clear business case for IS, making it difficult for companies to justify joining resource sharing networks [27]. This is worsened by high upfront costs for infrastructure and equipment, which can be prohibitive [28]. Financial barriers concern funding and specific investments [29], as companies often struggle to secure adequate financing for high investment costs.

Regulatory barrier-Regulatory frameworks often restrict or prohibit companies from exchanging waste, wastewater, and hazardous materials, preventing IS [30]. A key challenge is the lack of specific legal provisions for IS, which makes it difficult for companies to comply with environmental regulations and implement these practices. Legal limits on waste disposal can prevent waste from being classified as by-products and reused as raw materials by other firms. Regulatory complexity hinders new processes’ adoption and makes it hard for businesses to meet environmental standards.

Communication barrier-A major barrier is the lack of detailed qualitative and quantitative data on residue streams, which prevents companies from identifying symbiotic opportunities. This is worsened by the absence of information systems on material inputs and outputs. This limits the exchange of by-products between companies [31]. Communication barriers concern all issues related to the sharing of information between potential IS partners. Companies often hide or withhold information, restricting the exchange of data on the utility, origin, and availability of waste by-products [32].

Social and organizational barriers: Social and organizational barriers are focused on trust, communication, cooperation, and readiness to change. Low levels of trust, communication, and cooperation delay waste exchange initiatives and the development of symbiotic networks. A key barrier is resistance to change in organizational culture, which limits participation in collaborative relationships. Companies often struggle to modify processes and adapt them to new inputs, such as recovered waste or scraps [33]. Insufficient organizational support for integration, coordination, and communication further inhibits effective IS governance. Competition, weak commitment, low environmental awareness, and general resistance to changes often act as barriers. Many companies remain in the early stages of maturity and fail to recognize the potential benefits, with reduced participation in collaborative activities.

Deficits in administrative and governance capacity significantly slow the implementation of IS. A major governance challenge is insufficient administrative capacity, including weak organizational support for integration, coordination, and communication. This lack of institutional support is a key barrier that prevents companies from engaging in symbiotic relationships successfully [28].

Technical/technological barriers-The most important barriers that involve the physical exchange of materials, energy, and goods are technical and technological barriers. The complexity of symbiosis demands deep knowledge of material properties and cross-industrial cooperation, creating technical challenges that require more holistic thinking by regulators and industry [34]. Key barriers include the lack of suitable technology or sufficient capacity. IS projects often require technological changes that challenge participants, forcing them into transitional stages and adaptations. In heavy industrial areas and mixed industrial parks, technical barriers have historically been among the most significant obstacles [35]. Waste exchange networks also struggled with limited technical expertise and knowledge, restricting their role largely to providing online information. The infrastructure and equipment that are needed are additional obstacles due to costs that may be unsustainable for many firms. Companies also face readiness challenges, such as difficulties in adapting processes to use recovered waste or scraps as input. The flexibility of different systems, organization of the common exchange system, maintenance, the quality and the quantity of supply/demand are very common technical barriers in IS.

Geographical barrier-Additionally, in IS, the transport of goods between companies can be a barrier by itself. That is especially notable for sensitive by-products and waste (short lifetime of source) [36]. A specific case is heat transfer. Heat can be transferred only over short distances with higher efficiency [18]. Otherwise, there is a lot of heat loss. This is a so-called geographical barrier.

IS design can be done using different methodologies. LIAISE COST action report summarized methodologies that can be used in the design (identification, evaluation, and selection of solutions) [36,37]. They suggested flow analysis, emergy analysis, exergy analysis, Life Cycle Assessment (LCA), network analysis, and process integration (PI) tools. Moreover, methodologies can be divided by their purpose or step in the implementation of IS as “assessment and evaluation” methodologies [38], “optimization and mathematical modeling” [39], “design frameworks and step-by-step approach” [33], “platform and database development” [27], and “collaborative and participatory” methodologies [40]. This work focuses on technical solutions for IS. They are the basis for further calculations, agreements, regulations, and decisions in the implementation of IS. So, technical solutions can be designed using assessment and evaluation methods as well as mathematical modeling/optimization methodologies.

Evaluation and assessment methods are fundamental to IS design. They offer systematic ways to measure and analyze network performance in multiple dimensions. Practical tools include input-output matching for analysis of input types and output specifications. Furthermore, they include stakeholder analysis for understanding multi-party relationships and material and energy flow mapping. Modern comprehensive approaches integrate management and technical methods, such as environmental impact calculation, waste management accounting, and optimization assessment, to create holistic evaluation frameworks for IS networks [41]. Input-output analysis is an assessment approach that includes Ecological Input-Output Analysis (EIOA). EIOA offers a comprehensive model that captures the economic, environmental, and social behavior of industrial ecosystems and their detailed interrelationships [10]. It tracks economic, material, and energy flows for comprehensive impact analysis in all three sustainability dimensions [10]. Complementing these, Material Flow Cost Accounting (MFCA) provides an economic and ecological appraisal method that evaluates environmental efficiency and supports planning, control, and decision-making for IS design [10].

Mathematical optimization and modeling provide powerful tools for designing IS networks by systematically finding configurations that minimize waste, costs, and environmental impacts. Mixed-integer linear programming (MILP) is a core method for large and complex problems in IS and PI [39]. Modern implementations couple MILP with database frameworks and waste exchange identification algorithms to minimize non-recycled waste [10]. However, fully integrated industrial ecosystems often exceed the capabilities of conventional optimization. Multi-objective problems can become too complex for traditional methods, prompting the use of hierarchical-Pareto and robust optimization to address both detailed technical issues and full network complexity [10]. The limits of standard MILP have also led to bilevel optimization, non-linear deterministic optimization, and stochastic methods for specific processing aspects (Table 1).

Agent-Based Models (ABM) offer well-suited analysis mechanisms such as life cycle impacts and network properties like resilience [61,62]. They can assess geographical effects on symbiotic relationships through multi-objective optimization while validating IS performance indicators. ABM is well suited for the development of real-time “what-if” strategies [63]. These models help researchers anticipate the effects of small behavioral changes caused by agents or changes in social, natural, or economic subsystems [64]. They support the assessment of technological and organizational design choices in symbiotic networks and help identify the transition pathways that are likely under different intervention scenarios [42] (Table 1).

Flow analysis (Material and Energy Flow Analysis [MEFA]) is a systematic method used to provide detailed quantitative descriptions of material and energy flows per sector, indicating critical sectors in terms of resource consumption, waste generation, and identification of the most significant flows [65]. MEFA allows researchers to map and quantify metabolic flows in systems with their sectors, providing essential information to understand resource utilization patterns [66]. This methodology tracks the input, output, and transformation of specific material and energy resources through a system of interest, using existing business practices, databases, inventories, and surveys as its primary source of data [67]. This approach has proven to be valuable for improving the understanding of economic dimensions and exploring opportunities for efficiency and recovery in various systems [68] (Table 1).

MEFA, combined with LCA, assesses the environmental burdens of material flows throughout life cycles, revealing net gains and shifting burdens in symbiotic relationships [69]. Network analysis with MEFA maps material, financial, and relational interactions between IS actors [67]. Input-output analysis, including Leontief matrices, is a key industrial ecology tool in computable general equilibrium models [70]. Waste flow analysis, combined with MEFA and production matrices, supports models such as the IS “system waste flow metabolism analysis” [71]. “Dynamic decision support systems” integrate Mass Flow Analysis (MFA) and LCA to track by-product flows and quantify levels of symbiosis in EIP [72] (Table 1). Substance flow analysis and ABM, often coupled with system dynamics and hybrid modeling, further extend MEFA applications [70]. The design for the environment sets MEFA together within integrated industrial ecology, promoting eco-efficiency, dematerialization, and analysis of urban/industrial metabolism [70].

Emergy analysis is a quantitative method that values resources, services, and commodities in a common unit of solar energy. It enables the comparison of all resources [49]. Moreover, emergy represents the total available (embodied) energy required directly or indirectly in a system [52]. This method calculates flows of material, energy, information, and value in natural and socio-economic systems using the value of emergy [53]. It is especially useful for evaluating the sustainability of industrial ecosystems through emergy-based indices that capture waste treatment, recovery, reuse, and recycling while accounting for all material and energy flows. These indices quantify environmental, economic, and overall sustainability performance [10]. Applications show that urban-IS systems can reduce total emergy consumption by 12% when material flow analysis is combined with emergy analysis [73] (Table 1). This method has also been used to optimize eco-industrial park operation under uncertainty, identifying Nash equilibrium solutions that balance profit and sustainability [74].

Exergy analysis defines the maximum work that is accessible when a resource becomes in thermodynamic equilibrium with its surroundings through reversible processes [57]. In industrial ecology and symbiosis, exergy analysis supports the shift from linear to closed-loop systems, turning material and energy flows once treated as waste into resources for existing or new processes. Its main strength is to express all physical phenomena in terms of a single form of energy. It is based on natural or artificial resources, processes, or emissions. They can be consistently evaluated from an exergy perspective [75]. It also assesses industrial processes through exergy balances, quantifying and tracking inefficiencies to identify improvement opportunities with all relevant variables such as temperature, pressure, and composition [57]. In IS, this is crucial, because in all material and energy transformations, exergy is lost through irreversibility [75] (Table 1).

LCA assessment is one of the most widely used tools, providing a comprehensive method for quantifying all materials and energy used in industry. It identifies IS opportunities and measures environmental impacts [41,76]. The cradle-to-gate approach in LCA applies a life cycle perspective that looks beyond individual facilities to assess environmental impacts across all stages of the product life cycle. Since IS relies on cooperation between multiple companies, the LCA system is crucial to avoid pollution transfers between plants and the shifting of burden between impact categories [73]. LCA is widely used to confirm the environmental benefits of IS networks and to guide the valorization of by-products [77] (Table 1). It enables a multilevel assessment of environmental performance for individual or combined waste-resource exchanges [32].

Network analysis uses quantitative methods to study the physical and social interactions between entities in a system. It is presented as a network of nodes (entities) and links (relationships). It can model links such as material and energy flows, information, financial transactions, and social interactions. In the IS field, four related methodologies are used: social network analysis, stakeholder value network approach, ecological network analysis, and food network analysis. This methodology analyzes the structural characteristics of symbiotic networks, including size (nodes and relationships), density, clustering coefficients, information transmission speed (characteristic path length), centrality, and overall complexity (Table 1). These features reveal local and global properties of symbiosis networks and guide the design and construction of effective symbiotic systems [78].

PI contains various tools based on Pinch technology (Appendix 1). Pinch analysis has been adapted for the integration of waste and energy in IS sites. It promises benefits in IS engineering design. At the operational level, simulation-based optimization uses infinitesimal perturbation analysis. It can determine optimal production policies and stock levels for IS networks [79]. Integration with Pinch technology can play a vital role in IS design by identifying opportunities for heat exchange and energy optimization between different processes and industries. Pinch technology provides a systematic approach to analyze energy flows and identify potential areas for heat recovery and optimization [11].

Continuous processes in chemical plants, refineries, and power plants can be easily integrated [80]. Pinch analysis is particularly useful because of its steady-state nature. The advantages of Pinch analysis for continuous processes include the ability to identify optimal heat integration possibilities, to minimize energy consumption, and to reduce operating costs. Additionally, Pinch analysis allows for the identification of minimal hot and cold utility requirements as well as the determination of optimal process heat exchange targets.

Pinch analysis in continuous processes effectively optimizes energy usage, minimizes waste, and improves overall process efficiency. This method is easily applicable to continuous processes because of their consistency and predictability. This allows for more accurate and reliable analysis. The first step in the integration process is data collection. In this step, values of temperatures, flows, and other parameters of interest for possible heat exchange between streams are collected. The collected data are used for the design of composite curves. The method creates a chart of hot and cold composite curves based on hot and cold streams. That chart is used to identify the Pinch temperature and the heat recovery potential. Both curves are used to create a Grand Composite Curve (GCC). The construction of a GCC is used for the analysis of overall energy integration opportunities within processes where selected streams are active. As a result of heat integration with Pinch technology is the Heat Exchanger Network (HEN). That is, a system of heat exchangers that connects selected streams for heat transfer between themselves. The design is based on mathematical optimization techniques or graphical methods. This solution maximizes heat recovery and minimizes utility consumption (fresh utility supply) [81].

On the other hand, batch processes are characterized by discrete, non-continuous operations where production occurs in batches or cycles. These processes present unique challenges for the application of Pinch analysis due to the variable nature of streams. PI of batch processes is related to time-dependent streams and the specific time of heat recovery. That is the main difference from continuous processes. Batch processes show changeable operating conditions. That makes it difficult to use steady-state assumptions. Optimal timing for heat recovery within batch processes is crucial. That impacts the effectiveness of energy optimization and heat exchange. Very important characteristics of batch processes are repeatability or non-repeatability of streams/processes and formation of specific time slices (process sequences) [82]. HEN design for batch processes requires a dynamic approach for the time-dependent nature of these operations. The repeatable time slices refer to process steps that occur identically in each batch cycle. This allows for more consistent heat integration. Moreover, the non-repeatable time slices correspond to specific process steps that occur intermittently or with variations between batch cycles. These time slices in batch processes are prerequisites for successful Pinch analysis of the process dynamics and the identification of opportunities to capture and utilize heat across repeatable and non-repeatable time slices. Furthermore, the complexities of heat recovery based on timing within batch processes are essential to achieve effective energy optimization. Considering the evolving temperature profiles and heat transfer requirements throughout the batch cycle, engineers can strategically plan and implement heat recovery strategies to maximize the overall energy efficiency of the batch process. Solutions explore strategies for energy storage, intermediate heat exchange, and flexible utilities used to optimize energy utilization during batch operations [83,84,85,86,87]. The application of Pinch analysis techniques is to identify the minimum energy requirements for each batch and optimize energy usage in multiple production cycles.

Moreover, there is Pinch technology based on material recovery (mass Pinch technology), minimization of emissions (footprint Pinch technology), optimization of supply chain (supply chain Pinch technology), and optimization of water and wastewater (water Pinch technology). All these methodologies are like heat Pinch technology, and their main characteristics are explained in the table in Appendix 1.

All these developed methodologies of PI with Pinch technology have a positive impact on IS design. For a better understanding of the benefits of Pinch technology and the certain issues of other methodologies, the comparison table is prepared. Table 1 compares Pinch technology with other IS design methodologies. There are also limitations of the given methodologies and Pinch technology.

Pinch technology was primarily invented and applied in production systems between different production processes (in the same factory). Moreover, it can be used between different factories (companies), within the IP, and even at the regional level. However, IS has different levels of application. It can be applied between companies inside the same IP, where the waste and by-products of one company are utilized as input by another company. This type of symbiosis is “on-site” IS. The wider symbiosis can integrate multiple IPs or even entire regions, where the by-products and waste streams of one industry are utilized as input by another industry, creating a closed loop of resource exchange and minimizing waste generation. And finally, IS can be applied at a national or global level, where countries or regions collaborate to optimize resource utilization and waste management on a larger scale. The last two levels are performed between companies in different places. That kind of IS can be called “virtual” because they are not visible as IS participants. Therefore, integration of the system with Pinch technology can only be performed on on-site IS, with the exception of the supply chain Pinch technology. The implementation of Pinch technology requires a deep understanding of processes and systems involved, as well as accurate data on heat and mass flows (shared information) [88].

This collaborative approach can bring numerous benefits. Some critics argue that it can limit the autonomy and decision-making power of individual companies, potentially hindering innovation and progress. Positive and negative experiences can influence the way integration has been done between companies. As seen earlier, integrating different processes is easier in continuous processes. This integration can work perfectly and be synchronized. There is another question: what if a malfunction happens in one of the integrated parts? That will stop the first process, and automatically the other integrated part must be stopped. Therefore, a reserve plan must exist. In case of heat exchange, the other integrated continuous process must have active connections to hot or cold utilities. In the event of a malfunction, the production cost will increase. The integration of two continuous processes is robust and has no flexibility in realization. What should be done for better flexibility? Flexibility makes all integrated companies more independent. Therefore, flexibility can be higher if the system of integration between companies is based on batch processes or there is some storage system between connected parts [105]. Source delivery from other companies does not need to be used when supplying the system. That means that the source (heat, fuel, raw materials, water, etc.) can be delivered into storage, from which the second or third system can take without interruptions for its purposes. In this case, the optimal costs can be achieved with good design of storage systems (size, materials, connections, etc.).

Storage systems offer excellent flexibility between integrated systems. Inter-company IS is questionable when companies have different development rates [105]. When one company wants to increase production, it might need more sources delivered by symbiosis from other companies. That means other companies must increase their productivity or order the same resource from outside the IS. From this point of view, integration, as well as the IS, interrupts or stops the independence of other companies from increasing production capacity. This can destroy the IS by breaking or canceling already signed contracts and agreements between companies.

The use of Pinch technology for IS design depends on many factors that are common to all methodologies. Those factors are barriers or limitations due to obstacles on the part of some parties in IS. Barriers can originate from companies (internal or external sources), general barriers to energy cooperation, or specific energy sharing solutions. It can be related to intra-company measures, allocation, theoretical solutions for energy cooperation, and the level of matching with designed instruments to overcome all those barriers [118].

De Canio [119] explained “the efficiency paradox” related to missing profitable energy efficiency measures. Implementing technologies (especially green technologies) that will improve efficiency can cause obstacles to sustainability and not always produce benefits or expected profits. Sometimes, investment makes a profit and improvements but might not ensure overall sustainability and resource efficiency [120]. Here, visible factors such as piping distances, flow fluctuations, and availability of utility systems influence that.

Roden and Moser [118,121] classified barriers that influence energy integration. Some of them are barriers to the implementation of Pinch technology in the creation of ISs. The lack of knowledge directly influences the development of solutions and the use of Pinch technology. Internal competition for capital prioritization of non-energy investment, not having own funds, lack of acceptability of long payback times, retrofit design costs, fear of hidden costs, uncertainties and unknown risks, retroactive changes in renewable energy technologies, fear of unreliable business relations, and uncertainty in energy prices indirectly influence the implementation of the methodology. These are mainly economic considerations for companies that want to implement IS but have some prejudices or economic issues.

New solutions require new technology and equipment [122]. Therefore, all staff need additional training. There can be problems in adapting to new working environments, insufficient skills for non-core business issues, limited time and resources for non-core business issues, low motivation for the implementation of accepted rules for cooperation between companies, and the implementation of agreed responsibilities (for energy distribution, cross-sectional cooperation, poor work coordination of common systems, unification of implemented standards, managerial changes, and coordination bodies). Fears of business distortions, supply quality issues due to supplier changes, and behind-the-scenes maneuvering can also arise from direct market competition between companies in symbiotic systems. All of these are social and managerial barriers that also influence the choice of the solution.

Barriers that influence the framework in the implementation of designed solutions can be incomplete political strategies for energy, infrastructure uncertainties, regulations that can be obstacles for the use of certain technologies, lack of incentives, no legal solutions for pipelines that need to go through private properties, unification of local energy taxes, registered energy suppliers for managing exchanged energy, issues in case of multiple registered energy distributors, and regulations for direct exchange between two companies. Technical barriers that minimize the implementation of Pinch technology solutions could be the use of different industrial standards, lower expertise in using new technologies, waiting for the adoption of other companies for suggested designs, gaps and mistakes in matching, low technology readiness, long distances for exchange with high energy losses, having no technical solutions in managing by-products, using old infrastructure, uncertainty in the quality of exchanged energy, limited understanding of technical options, having no technological forecasting, intermittency of supplied energy or renewables, requiring energy storage [18,105]. The exchanged energy must be measured, controlled, and registered. These obstacles can make excellent solutions acceptable to companies. For good measurement, registration, and control, a good information system with a lot of sensors, meters, and data storage is needed. Every change or malfunction in one company can disrupt supplies for other companies. Therefore, every change must be detected and shared with others to take action to avoid bad consequences. Equipment and information systems are required, such as big data management, waste heat exchange measurement systems, implemented Internet of Things (IoT) systems, cybersecurity protocols for the privacy of data and protection of the most vulnerable points, bi-directional flow of energy and information, provision of sensitive business data, and communication between relevant people in all connected companies at different levels and times. Very important is empathy for other companies’ needs in the symbiotic system and avoiding uncertainty about who manages the new exchange system between them.

Design steps for technical integration systems for IS can be determined based on all possibilities that Pinch technology can provide as a tool. Figure 4 shows different Pinch methodologies used in PI between two or more production facilities. The urban area system can be included as supply/demand points for mass or heat [123]. In addition, renewable energy sources can also be integrated [124,125]. As with every Pinch methodology, information sharing is an important starting point. In this case, the information does not need to be detailed for the whole process of what happened in the internal systems of each company [31]. Detailed information is needed on selected streams, their quantity and quality of heat/mass/concentration, and their timelines (in case of batch processes). That starting point is enough for the design of HEN/MEN solutions, as well as possibilities in need of storage systems or additional equipment [126,127,128]. All of these define the exchange dynamics. When all possible solutions are generated as alternatives, they can be compared on the basis of economic optimization (as a step in the Pinch methodology) [18]. When basic technical solutions are made, the next step involves footprint Pinch technology. It optimizes environmental impact [129]. Already determined solutions must satisfy environmental regulations and laws. If that is not satisfied, it is returned for reconsideration. Solutions of footprint Pinch technology can lead to slight corrections in already generated alternative solutions. When footprint Pinch technology satisfies all rules and regulations, the technical design of integrative systems is ready for further management analysis. In this step, a common system for the transport of employees, the transport of goods, and products can be designed [31]. This can be based on supply chain Pinch technology. With this, Pinch technology can provide a whole technical solution in designing and applying IS in IPs. Exergy analysis can approve or disapprove of a potential loss of energy if the exchange is over long distances [58]. That is why the most optimal solutions require integration inside the industrial park or in nearby places that are within small distances. This is especially important for energy exchange, which can have very high transportation losses.

Pinch technology is not commonly used to create “virtual” or “on-site” information systems. There aren't many projects that use Pinch technology. Most of them are theoretical solutions. There, they show good performance in establishing symbiotic systems. In these cases, new modifications made in Pinch technology improve PI methodology. Primarily includes R-curve, TSP, and SSSP analysis. Moreover, PI methodology can be based on energy, exergy, or emergy when heat and electricity are concerned for integration systems. The best results in IS design are shown only in on-site integration or in-site ISs. Additional problems appear with integration into virtual IS. Basically, distance is the main obstacle.

However, challenges persist, particularly for virtual symbiosis involving geographically dispersed sites. Technical obstacles include the need for continuous supply-demand matching, flexibility, equipment readiness, and storage solutions, which are critical to maintaining system robustness. Non-technical barriers, such as intercompany agreements, regulatory constraints, economic considerations, education gaps, and information sharing, also significantly impact the adoption and success of Pinch-based IS designs. Awareness and knowledge dissemination among both technical and non-technical stakeholders are essential. Furthermore, developing accessible design algorithms and frameworks that can be utilized by various professionals involved in IS planning will facilitate wider implementation. Integrating Pinch technology with complementary approaches, such as supply chain optimization and environmental footprint analysis, can provide comprehensive technical solutions to foster sustainable industrial symbiosis.

Pinch technology has limitations for IS. They can be summarized as follows:

Pinch technology offers many benefits compared to other methodologies used in IS design. They are as follows:

Pinch technology is used for IS design, but each type of Pinch technology is used separately. That makes it low impact to get a good Pinch-based solution. Therefore, all types of Pinch technology must be included, as suggested. A combination of these different types covers gaps in each separate Pinch technology solution. It can include heat, mass, and supply chain, as well as environmental influence (footprint). The suggested approach also has limitations that need to address blockchain and other economic relations, as well as areas that are not covered by technical sciences.

Overall, Pinch analysis provides a structured and potentially robust basis for the technical design and optimization of IS systems. However, its full deployment remains constrained by technical, organizational, and regulatory limitations. Mitigating these barriers through targeted capacity building, inter-organizational coordination, and continued methodological refinement is likely to be critical for enabling broader adoption and improving the effectiveness of IS implementations. The proposed multi-method toolkit is intended to support the practical enhancement and operational performance of IS systems. In the future, this algorithm needs to be more systematically developed.