## 2 Literature Review  
Causes of work-related accidents on scaffolding were investigated by the authors of articles [10; 11; 12]. [PERSON] et al. [10] indicate that the main cause of falls from roofs and scaffolding is a lack of protective barriers. [PERSON] et al. [11] found that the most common causes of these accidents were the following: the use of faulty elements, arbitrary modification of the scaffolding structure, a lack of barriers, and also easily detectable structural errors. In turn, the results of studies conducted in the UK by [PERSON] et al. [12] revealed that the most common causes of accidents were: violations of existing regulations, ignorance of the principles of safe work practices, insufficient equipment of employees and workplaces in measures of individual and collective protection and also an improperly conducted construction process. The above results are also confirmed by [PERSON] and [PERSON] [13]. [PERSON] and [PERSON] [14] showed a strong statistical correlation between the defects in a scaffolding structure and the risk of falling, and also between applied practices in the area of work safety on scaffolding and the competence of people conducting trainings. Studies carried out by [PERSON] et al. [15] have also shown that work safety on scaffolding can be improved with the use of appropriate training methods. [PERSON] et al. [16] analyzed falls from height in Hong Kong. They classified the factors affecting the accidents into four classes, namely ill planning, violation, hidden hazards created by others and incapable staffing. In addition, the authors identified irregularities in the management of a building site, which included: a lack of risk control, the use of unsafe methods and procedures and also improper training and supervision of work. The research presented in the above-mentioned articles is of a statistical survey nature. On the basis of the analysis of a specific set of accidents, the percentage share of different causes that lead to the occurrence of accidents were identified. A methodological approach to the analysis of the causes of accidents in the construction industry is presented by the authors of publications [17; 18; 19; 20]. [PERSON] et al. [17; 18] classify the root causes of an occupational accident on a construction site as: failing to identify an unsafe condition that existed before or after an activity started; deciding to proceed with a work activity after a worker identifies an existing unsafe condition; deciding to act in an unsafe manner regardless of initial conditions. [PERSON] et al. [19; 20] indicate that conditions occurring throughout the 'life cycle' of scaffolding--including the phase of preparing documentation related to scaffolding, the selection of assembly elements, assembly and operation, and also dismantling of scaffolding--have a great impact on the occupational safety of scaffolding. Damage to some elements and also errors committed during individual phases can affect the occupational safety of a structure during its operation. According to the literature survey, the problem of occupational accidents involving construction scaffolding occurs in many countries. As already mentioned in the introduction, this problem is noticed, but is analyzed in various ways with the causes of accidents and their validity being classified freely. It can be concluded that there is a lack of unified methodology for identifying causes and assessing their validity. This methodology would allow the results obtained in different countries or regions to be compared, and appropriate conclusions on them to be formulated on their basis. Based on the conducted research and analyses, the authors proposed to fill in the gaps existing in this area, mainly through:  
* Developing a methodology for the classification of causes of accidents at work involving construction scaffolding, which is based on the division of causes into three generic groups: technical (\(T\)), organizational (\(O\)), and human (\(H\)).