### Related Work
Technological advancements have introduced various tools to facilitate work activities and improve hazard identification in the workplace. The construction sector has not been exempt from this progress [22]. However, the extent to which employees are willing to adopt advanced tools in their daily tasks and the potential challenges such equipment may pose during routine work activities remain a topic for further research. Occupational safety indicators can either be qualitative or quantitative in nature. These are based on measurements in the work environment or expertly defined evaluations and are used to determine whether a company, its organisational unit, or an individual meets the desired goals, which may be independently or legislatively defined. These indicators serve as the foundation for monitoring the implementation of safety plans and programs and act as a means in which to initiate preventive or corrective actions within the OHS system. Monitoring a large number of performance indicators is challenging and requires significant resources that smaller companies often lack. Therefore, it is convenient to select key indicators. Classifying these indicators into thematically related groups and arranging them hierarchically makes them suitable for ranking by means of multi-criteria analysis methods. Analytic hierarchy process (AHP) is often used for this purpose because of its hierarchical approach to problem analysis. It describes the decision-making process using objectives, aspects, and alternatives. By comparing pairs of aspects or alternatives, their relative importance is determined using numerical values from the Saaty scale. These values form the basis for obtaining the weights of aspects and ranking the alternatives. In occupational safety within the construction sector, AHP has been applied to tasks such as identifying risks during work planning [23] and construction site organisation [24],assessing the potential safety incidents [25; 26], defining the safety management system priorities [27], and reallocating the available safety resources [28]. However, it is not always possible to compare aspects or alternatives using precise numerical values, as required by AHP. To address uncertainty, [PERSON]'s fuzzy logic and fuzzy numbers (trapezoidal or triangular) are used, resulting in fuzzy AHP (FAHP). This approach increases complexity, as it requires applying fuzzy calculations and subsequently defuzzifying the obtained fuzzy weights to derive crisp values for final comparisons and rankings. The use of fuzzy numbers enables comparisons using linguistic variables to describe ranges of values. FAHP has been used in occupational safety in construction, either independently or in combination with other methods, for tasks such as analysing the safety risks on construction sites [29], identify accident causes [30], assessing safety conditions [31], and defining priorities or selecting key indicators [32; 33]. This paper presents a hybrid approach for selecting key indicators to improve the OHS system. The approach combines the expert selection of key indicators of occupational safety with their ranking using FAHP. The FAHP method was chosen because the proposed classification of indicators has a hierarchical nature, similar to the decision-making hierarchy used in FAHP. The process involves the pairwise comparison of elements using a fuzzy scale, which accounts for uncertainty. Additionally, both qualitative and quantitative indicators can be considered during ranking, further supporting the choice of this method. Based on the defined classification, the procedure was applied to identify the key indicators for improving the OHS systems in small construction companies. The methodological approach is described in Section 2, while Section 3 demonstrates the application of the hybrid approach in the case of small businesses involved in window- and door-fitting activities. The results are discussed in Section 4, followed by the concluding remarks.