Design methods for Product–Service Systems in the context of energy efficiency and environmental sustainability

Recent decades have seen the dynamic development of the Product-Service System (PSS). This concept is considered one of the best instruments for enabling traditional industrial companies (COM) to transition toward energy-efficient, resource-saving, and environmentally friendly business practices. Furthermore, it enables extending product life through systematic maintenance and reuse. It also enables the generation of economic benefits and provides entirely new value for the development of industrial COM. The potential of PSS regarding environmental (ENV) and energy (EN) issues makes its widespread use justified, especially in the industrial sector This paper utilizes a multi-stage research methodology. A three-stage systematic literature review (SLR) constitutes a key step in this methodology. This approach allows for the study of PSS design methods (PSS DM) in the context of EN, sustainable transformation (ST), and environmental protection (EP). It also allows for the description of interconnections and relationships, ensuring a comprehensive understanding of PSS design in the context of EN, ST, and EP. This represents a novelty that has not yet been studied and published in the scientific literature on EN, sustainable development (SD), EP, and management. The results of this work indicate that the scientific literature contains 110 PSS DM, 30 of which do not address EN, ST, or EP. Another 80 PSS design methods take these criteria (CRI) into account either fully or partially. By conducting a comprehensive analysis of 80 PSS DM using 26 selected CRI related to EN, ST, and EP, we aim to highlight the issues identified in the context of PSS design. The most important features of design methods in this area, along with their gaps, are also highlighted. Furthermore, the current state of the literature on this phenomenon is critically reviewed. Furthermore, the paper introduces a new classification of PSS DM that allows simultaneous assessment of the breadth, intensity, and depth of integration. It is based on four main indicators: PSS Integration Score (PSS IS), Direct Integration Count (DIC), Direct ratio (DR), and Coverage ratio (CR). Based on the four indicators presented, 80 PSS DM were classified into four groups (T1 - Systemic Integrators, T2 - Focused Integrators, T3 - Exploratory Integrators, and T4 - Limited Integrators) reflecting different integration profiles. Finally, directions for future research are identified.