# Using Digital Twin in a Shipbuilding Project
## 5 Results and Discussion  
As the result of the outfitting activities being performed in earlier stages of the cruise vessel's construction, particularly during the blocks's (on-block outfitting phase), the analysis of the collected data (Table 3) shows a significant reduction in the number of working hours for outfitting, up to 30%, depending on the profession. There are about 10% savings in the total number of ship outfitting working hours on average. It can be noticed that the research results show no improvement in reducing the number of working hours for piping assembly; on the contrary, an increase of almost 18% occurred. The reason is that pipe assembly works were a focus of advanced outfitting from the very beginning of the development and the application of the subject technological approach in question to the \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Items** & **Passenger Vessel** & **Cruise Vessel** & **Equation** \\ \hline Man-hours in the build process, total, \(MH\) (h) & 2,027,647 & 1,230,683 & \\ \hline Number of injuries at work, total, \(NI\) & 64 & 23 & \\ \hline Lost injury time, \(LT1\) (h) & 31,960 & 4208 & \\ \hline Injury frequency rate, FR & 33.06 & 18.69 & FR = (\(NI\times 106\))/\(MH\) \\ \hline Injury severity rate, SR & 16.51 & 3.42 & SR = (\(LT1\times 1000\))/\(MH\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Injuries at work. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Passenger Vessel 1**} & \multicolumn{2}{c}{**Cruise Vessel 1**} & \multicolumn{2}{c}{**Difference (\%)**} \\ \cline{2-9}  & **Man-Hours** & **Man-Hours/CGT** & **Repairs** & **Man-Hours** & **Man-Hours/CGT** & **Repairs** & **Man-Hours/CGT** & **Repairs** \\ \hline Welding in total & 536,918 & 14.08 & na & 353,586 & 12.17 & Na & \(-\)13.55 & na \\ \hline Assembly—machinery & 147,935 & 3.88 & 10.8 & 78,159 & 2.69 & 2.2 & \(-\)30.64 & \(-\)79.63 \\ \hline Assembly—piping & 238,498 & 6.25 & 27.1 & 213,714 & 7.36 & 8.3 & 17.63 & \(-\)69.37 \\ \hline Assembly—locksmith & 159,498 & 4.18 & 22.6 & 109,850 & 3.78 & 1.7 & \(-\)9.59 & \(-\)92.48 \\ \hline Assembly—electro & 268,979 & 7.05 & 11 & 153,131 & 5.27 & 5.7 & \(-\)25.27 & \(-\)48.18 \\ \hline Assembly in total & 814,910 & 21.37 & na & 554,854 & 19.1 & Na & \(-\)10.62 & na \\ \hline Shipbuilding process in total & 2,027,647 & 53.17 & na & 1,230,683 & 42.36 & Na & \(-\)20.32 & na \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Working hours—welding (total) and outfitting. shipbuilding process, regardless of the production program of the shipyard [24]. Hence, the scope of advanced outfitting with the piping components has increased throughout history and is perfected in performance. However, the application of a virtual ship model, today in Digital Twin form, achieves a significant reduction in the consumption of working hours to eliminate errors in assembly, both in pipe assembly activities and all other outfitting professions, with an emphasis on locksmith work--or a 90% improvement--all as a result of redirecting the activities of advanced outfitting towards the blocks's direction phase. Empirical and statistical data of the observed shipyard indicate that, today, it completes approximately 70% of the total ship outfitting in the phase of construction before lifting blocks onto the slipway, with a tendency for further growth, compared to the indicators before applying the 3D ship model in the form of a digital prototype--approximately 31% in the construction of a cargo vessel [23], or an average of 40% (Europe) up to 50% (Japan) in the construction of a cruise vessel [24].