## 4 Results
Figure 5: Weighted Ishikawa diagram with main cause weights. \begin{table}
\begin{tabular}{c c} \hline \hline
**Main Causes** & **Sub-Causes of the First, Second, and Third Levels** \\ \hline  & [2.2.2.1.] Air quality \\ \hline  & [2.2.2.2.] Noise \\ \hline  & [2.2.2.3.] Lighting \\ \hline  & [2.2.2.4.] Personal space \\ \hline  & [2.2.3.] Ergonomic aspects \\ \hline  & [2.2.3.1.] Repetitiveness of activities \\ \hline  & [2.2.3.2.] Hand strain \\ \hline  & [2.2.3.3.] Uncomfortable posture \\ \hline  & [2.2.3.4.] Annoying vibrations \\ \hline  & [3.1.] Improper operation \\ \hline  & [3.1.1.] Non-compliance of operational activities with the requirements of the company and IMO regulations \\ \hline  & [3.1.2.] No regular inspections \\ \hline  & [3.2.] Ship failures \\ \hline  & [3.2.1.] Damage to the navigation system \\ \hline  & [3.2.2.] Loss of hull tightness \\ \hline  & [3.2.3.] Damage to the deck equipment \\ \hline  & [3.2.4.] Main engine failure \\ \hline  & [3.2.5.] Failure of automatic equipment \\ \hline  & [3.2.6.] Failure of auxiliary machinery in the engine room \\ \hline  & [3.2.7.] Damage to pipelines and fittings \\ \hline  & [4.1.] Voyage planning errors \\ \hline  & [4.1.1.] Incomplete documents \\ \hline  & [4.1.2.] Non-compliance with certified system(s) \\ \hline  & [4.2.] Errors in the management of the ship’s crew \\ \hline  & [4.2.1.] Errors in the delegation of tasks \\ \hline  & [4.2.2.] Inadequate staff appraisal system \\ \hline  & [4.2.3.] Inadequate monitoring \\ \hline  & [4.3.] Incomplete ship operating report \\ \hline  & [4.4.] Inaccurate inspection of the ship \\ \hline  & [4.4.1.] Internal audits by the company or external audits by the charterer \\ \hline  & [4.4.2.] Port inspections \\ \hline  & [4.4.3.] Flag State inspections \\ \hline  & [5.1.] Cargo shifting \\ \hline
5. Other factor & [5.2.] Drifting wreck \\ \hline  & [5.3.] Terrorist attack \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._As for the leading causes, i.e., based on the comparison matrix, relative weights were determined for the individual first-, second-, and third-order sub-causes. Subsequently, absolute weights were selected for the sub-causes based on the relative weights. The relative weights were multiplied by the value of the relative weight of the leading cause to which the sub-cause belonged. This can be written with a simple equation [91]:  
\[\text{W}_{\text{a.sn}}=\text{W}_{\text{r.i.c}}\,\text{W}_{\text{r. sn}}\]  
where  
\(\text{W}_{\text{a.sn}}\)--Absolute weighting of sub-causes of n order,  
\(\text{W}_{\text{r.i.c}}\)--Relative importance of the main cause,  
\(\text{W}_{\text{r. sn}}\)--Relative weighting of sub-causes of n order. Based on the results obtained, which were ranked in descending order of importance, cumulative weights were determined for the defined sub-causes. A reference field was calculated, as shown in Table 3. The value of the reference field was obtained by multiplying the value of the cumulative weight by the value of N = (55 \(-\) n), where 55 is the number of all reasons, and n is the number of the next sub-reason [92; 93]. The grey color indicates the causes with the most significant impact on marine casualties. The cumulative weights presented in Table 3 are the coordinates of the Lorentz Curve and the basis for a stratification analysis based on the Pareto Rule. Thus, a group of influential and less essential factors influencing marine casualties was identified. The data obtained were transferred to the graph shown in Figure 6.  
The so-called \"reference area\" was taken as the index of division. This is the rectangle's area defined by the Lorenz Curve's inflection point. This area reached its maximum for the 23 sub-causes and amounted to 9.520, thus constituting the limit of stratification and definitively determining the division into the group of essential sub-causes A (marked in grey in Table 3) and the group of less important causes B. The most important and frequent causes included those from the \"Management\" and \"Human\" groups.