Grzegorz Ginda

The article assesses the energy potential of biodegradable municipal waste in the Krakow Metropolitan Area, analyzing the feasibility of using derived biomethane for residential heating by 2050. Framed within the circular economy and the European Green Deal, the study highlights a significant technological gap in Poland, contrasting it with successful models in Austria, Germany, and Italy. Empirical data from 2023–2024 indicate that kitchen waste (code 20 01 08) is an optimal feedstock for methane fermentation due to its stable annual flow, whereas green waste (code 20 02 01) presents challenges due to high seasonality. Simulation modeling suggests that annual biomethane production from kitchen waste could range from approximately 1.23 million m³ (Variant 3) to over 1.42 million m³ (Variant 4). A key finding is the synergy between waste-to-energy transformation and building thermal modernization. By reducing energy demand, the consistent volume of kitchen waste processed from 2024 could potentially supply heating for between 4928 and 8180 apartments by 2050. Ultimately, the research underscores the role of metropolitan integration in achieving sustainable development goals, enhancing regional energy security, and reducing emissions.

Effective project selection is a critical determinant of success for Design for Six Sigma (DFSS), particularly in automotive environments defined by high technical complexity and constrained resources. Because these selection tasks involve competing priorities, they are fundamentally multi-criteria decision-making (MCDA) problems that directly impact a company’s economic performance. This paper proposes a hybrid decision-support framework that integrates the Analytic Hierarchy Process (AHP) with a normalized scoring model. In this approach, classical AHP pairwise comparisons are used to derive consistent criteria weights, while project alternatives are evaluated on a 1–10 normalized scale to ensure the model remains scalable and practical for an industrial setting. The framework was empirically validated through a case study in an automotive company evaluating twelve DFSS project concepts. The results reveal that experts prioritize Product Quality (33%) and Cost/Functionality (33%) above all other factors, with these two criteria accounting for 66% of the total decision weight. Furthermore, the study established classification rules where projects scoring above 7.2 showed high implementation potential, while those below 5.2 were frequently discontinued. This structured approach enables a transparent and justifiable prioritization process that supports economic and operational sustainability by significantly reducing wasted engineering hours and prototype costs.

Six Sigma offers a robust and widely applicable methodology for tackling practical decision-making challenges across various industries. Complementarily, the Analytic Hierarchy Process (AHP) and Analytic Network Process (ANP) provide a universal framework for decision support in diverse applications. Given their inherent strengths, these methodologies appear to be a natural fit. However, it remains uncertain whether this synergistic potential is fully leveraged within current Six Sigma practices and its derivative methodologies. This paper presents a comprehensive literature survey to ascertain the extent to which Six Sigma practitioners utilize AHP/ANP. The findings from this survey will then be used to identify current trends and highlight existing gaps in harnessing the full potential of AHP/ANP within the Six Sigma framework.

Virtual reality (VR) can generate imaginative, interactive, and immersive worlds, emerging as a novel gateway for the next generation of computing platforms. Nevertheless, the human factors and ergonomics (HFE) challenges associated with VR headsets pose risks to the users physical and mental well-being and limit the widespread application of VR across various domains. In addition, research remains scarce addressing the optimal design of user interfaces (UI) in VR to ensure positive user experiences (UX). This paper offers a comprehensive overview of studies in the realm of HFE concerning virtual reality headsets, i.e., head-mounted displays (HMDs). This review paper explores and discusses HFE issues related to VR user interfaces (UI) and provides guidelines to enhance human-centered product development. It is important to note that these guidelines are regarded merely as a starting point for future research, as they necessitate validation.

Decision making is critical to the success of safety management in construction projects. Due to the simultaneous evaluation of numerous criteria and objectives, multiple-criteria decision making (MCDM) is essential for decision problem solving. Several MCDM methods are continuously being developed and are progressively used to solve real-world construction safety challenges. This study aimed to understand the progress of MCDM methods and their application in construction safety. A total of 52 articles were found after conducting a systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-analyses review method. The research trend is then described using bibliometric analysis in terms of the number of publications per year, sources of documents, influential authors and countries, highly cited articles and research areas. The findings indicated that the analytic hierarchy process (AHP) and its fuzzy version, FAHP, were applied mainly in construction safety research. The key areas where MCDM methods were focused on were safety risk assessment, safety culture and safety programmes. The study findings are expected to assist construction practitioners by allowing them to use the best and optimal MCDM method for problem solving related to safety.

In Poland, the potential for biogas production is high. important source of renewable energy and contributes to reducing the emissions of methane, a greenhouse gas. In this article, based on materials from the National Agricultural Advisory Centre (KOWR), literature, and statistical data, the implementation of the agrigas plant construction programme was evaluated in individual voivodeships. Based on the collected data, it was concluded that the most meaningful factors for the successful development of Polish agricultural biogas plants are biogas production technology, substrate availability, energy price from renewable energy sources, waste disposal costs, population density in the commune, and allocation of places in local spatial development plans (MPZP). DEMATEL technique was used to identify key development factors. The results of the study provide useful information for both government and local authorities in the search for effective ways to drive the sector's development.

Municipal district heating systems in Polish cities constitute important elements of these municipalities (and not only of their technical infrastructures). Due to the nature of the basic service that is provided - providing heat (and perhaps year-round comfort in the future) - these systems can be perceived as important parts of the social infrastructures of the cities, creating the appropriate conditions for the existence of people, the functioning of social infrastructure facilities, and the operations of enterprises. The need for heating companies to adapt to any changes in the requirements that arise as a result of the economic, social, environmental, and (increasingly) political and legal changes that take place in its immediate and distant environment requires the implementation of investments. However, the effects of such investments are multidimensional and largely difficult to measure; they depend on the passage of time and complex conditions that are related to the pursuit of sustainabledevelopment and security. Their reliable assessment therefore requires the use of appropriate tools. This paper is devoted to an analysis of the practical usefulness of multi-attribute decision-analysis tools in this context, taking various types of such tools into account as well as the conditions for their effective applications. The most promising of these tools is also introduced and discussed.

Sustainable development and environmental considerations have resulted in many cities around the world recognising the importance of non-motorised modes of transport. Problems related to the proper development and maintenance of cycling infrastructure have already been the subject of various studies. However, they have mainly dealt with the identification of factors influencing the development of cycle paths and the optimisation of the design of safe and comfortable cycle routes. The influence of individual factors on each other and on the development of cycling infrastructure has not been studied. The research aims of this article are to identify which factors influence the development of bicycle infrastructure, their role and interdependence, and their prioritisation. It also looks at whether there are differences between the opinions of bicycle users and experts professionally involved in the development of bicycle paths in assessing the importance of the factors indicated. As a result of the study, eight factors influencing the development of bicycle infrastructure were identified. Based on the opinions of cyclists and experts, the nature of each factor was analysed. Taking into account the complex relationships between the factors, the key factors contributing to the development of bicycle infrastructure were shown: (1) the planning of bicycle paths, taking into account the separation of individual paths and their continuity, consistency, and length; (2) legal regulations promoting cycling in terms of transportation policy; (3) the elimination of obstacles; and (4) the design of bicycle paths, taking into account the safety, space management, terrain, and attractiveness of the surroundings. The results for both groups of respondents were compared. They indicate that both groups of respondents reported the same factors as the most important, with the only differences being in the order of the importance of the factors. The academic value of this work lies in showing the usability of the underrated original version of DEMATEL methodology in the considered area for key factors. The practical significance of this paper is the provision of a rather simple, yet reliable, tool for addressing the complexity of interrelated issues that make the development of urban infrastructure a cumbersome task.

Agricultural biogas plants are a renewable source of energy and at the same time enable the disposal of biodegradable waste generated in agriculture and the food industry. In Poland, a program aimed at constructing agricultural biogas plants has been in operation since 2010 with the goal of producing 1.7 billion Nm³ of biogas, which has not been achieved. Factors that could influence the development of this energy source were identified based on a register of agricultural biogas producers from the National Agriculture Support Center and data from the Energy Regulatory Office. These factors are technology, substrates, state energy policy, profitability, population density in the commune and the spatial arrangement of the commune resulting from spatial development plans. A pairwise comparison analysis using the DEMATEL method was conducted for these factors. It allowed us to conclude that they are population density and the lack of local spatial development plans in most rural areas. The situation may be improved by the obligation to develop such plans for the entire area of each commune and by locating biogas plants near livestock farms and agri-food processing plants. The selected DEMATEL method is mature and comprehensively verified. It enables research to be carried out in other contexts, taking into account the correlations between factors. It is a universal method, and after collecting expert opinions, research can be expanded. The obtained results of the analysis will allow for further research by collecting the opinions of experts such as biogas plant users, local communities, local government officials and other stakeholders. In addition, further analysis of key factors will be carried out using the DEMATEL method for several scenarios. The PESTEL method will be used to identify key factors.