## 4 Discussion
Since the problem researched in the paper is fundamental in the sense of applied load and soil type, the conclusion regarding the Taylor Series, PEM and Analytical FOSM-N can be extended to the reliability analysis of footings in general, also taking into account more complex types of actions and ground layering  
For example, a reliability analysis of a footing embedded in coherent soil, loaded with different types of action, will include more random variables, and consequently a mathematically more complex reliability integral formulation. This will affect the shape of the actual PDF of FS and additionally contribute to the uncertainties in the first and second moments estimation. The results of the reliability method suitability assessment of the ULS of shallow foundation are in agreement with the results of the study dealing with embankment stability [1]. This study concluded that the Taylor Series and PEM methods are not appropriate for the estimation of the reliability of embankment stability and recommends using only the Simplified FORM method (Table 1). It is presumed that such a conclusion was reached based on the error sizes for the methods considered. The criterion defined in Section 2.4 was applied to the data from this study, and the results are shown in Table 9. The results obtained perfectly match the conclusions of the study authors, even though they did not explicitly list the criteria which led to their conclusion. The same criterion was applied to the data from the study (Table 2) which researched retaining wall reliability for three failure modes: sliding on sand, sliding in clay and bearing capacity (undrained) [2]. Unlike the previous two examples (shallow foundation and embankment stability), the performance functions are significantly simpler, which generally yielded smaller errors for all the methods used (Tables 10 and 11). The Simplified FORM method is suitable for the reliability assessment of all three failure modes, while PEM-N is not suitable for either. The Taylor Series-N method is suitable for reliability analyses of sliding on clay and bearing capacity, while the PEM-LN method is suitable for reliability analyses of sliding on sand and sliding in clay. Based on the results presented, a conclusion is reached on which methods are suitable for use in the presented geotechnical engineering tasks. In general, simpler methods are not recommended in everyday engineering practice without previous validation in the task at hand. Doing otherwise can lead to incorrect reliability measurements, which will be impossible to identify as an under- or overconservative solution. This is also applicable for more complex reliability analyses, such as the RBO, since these procedures use previously listed methods. Although not the subject of this paper, the reliability analyses showed significant differences in reliability indexes (ranging from 2.38 to 2.94) of the footing for different angles of internal friction. All analyses were performed for the ULS according to Eurocode 7, DA3, for the case when \(\mathrm{E_{d}=R_{d}}\). The target \(\beta\) value for the reference period of 50 years is 3.8 [17]. Calculated reliability indexes are significantly lower than the recommended value; therefore, a question of design procedures evaluation according to EC7 can be raised. The recommendation for further research is to analyse the reliability indexes of different types of geotechnical structure designed according to Eurocode 7 and the possible introduction of additional partial factors of safety elaboration regarding the degree of understanding of the site-specific conditions. A similar principle is prescribed in the Canadian Highway Bridge Design Code [38], which allows engineers to have their designs reflect the degree of uncertainties associated with the parameters and models used [39]. **Author Contributions:** [PERSON] and [PERSON] developed the main concept and conceived the research. [PERSON] was responsible for algorithms development, charts creation and he drafted the manuscript.