## 4 Results
### Process Time Analysis
This lead time only happens once at the beginning of the process. After the delivery, the elements are installed using a crane and on-site workers, and the joint concrete work is then completed. The rate of work consumption is based on Finnish construction productivity information Ratu cards, and it takes 0.19 h per concrete element per square meter to install. Table 3 illustrates the schedule comparison of all scenarios. We divide the whole construction process into three main stages: pre-construction, construction, and post-construction. The pre-construction in 3 DCP scenarios involves all the steps that need to be taken after the architectural design is ready, from the construction permissions being received from the authorities to initiation of the actual construction of the building. For the on-site conventional scenarios, pre-construction involves shipping the required steel, timber, and ready-mixed concrete. For the S7 prefabrication scenario, pre-construction involves extracting the concrete component configurations from the design model and the ordering, manufacturing, and shipping time for these components. The construction stage in the 3 DCP scenarios includes the steps relating to the printing of the walls and the reinforcement stages of the 3 DCP process until the printing is completed. For the on-site conventional scenarios, the construction involves formwork, reinforcement, concrete casting, and demolding and cleaning the molds. For S7--the prefabrication scenario--construction involves the assembly of concrete wall components and joint concrete work. \begin{table}
\begin{tabular}{c c c c c} \hline
**Scenario** & **Pre-Construction** & **Construction** & **Post-Construction** & **Total (h)** \\ \hline S1 (ONP-RND) & 11 h & 21.5 h & 3 d & 4 days 8.5 h \\ S2 (OFF-RND) & 8.16 h & 21.5 h & 14 d 7.5 h & 15 days 13.16 h \\ S3 (ONC-RND) & 2 h & 34.4 h & 28 days & 29 days 12.4 h \\ S4 (ONP-RECT) & 11 h & 27.3 h & 3 days & 4 days 14.3 h \\ S5 (OFP-RECT) & 8.16 h & 25.3 h & 14 d 7.5 h & 15 days 16.96 h \\ S6 (ONC-RECT) & 2 h & 35.8 h & 28 days & 29 days 13.8 h \\ S7 1 (OFC-RECT) & 6 months 1 h & 30 h & 1 days & 6 months 2 days 7 h \\ \hline \end{tabular}  
* Not fully comparable with other scenarios since the data take the subcontractor’s perspective of buying the modules from a prefabricated module supplier rather than the prefabricated module manufacturer itself.  
\end{table} 
Table 3: Schedule comparison of all scenarios. Figure 9: The process map for Scenario 7. The post-construction stage in 3 DCP scenarios includes disassembly and relocation of the printer, drying of the off-site printed wall, transportation to the site, and assembly of the wall modules. For the on-site conventional scenarios, the only post-construction activity is the drying of the concrete, which can be excluded from estimating the time taken to build 100 houses consecutively. For the S7 prefabrication scenario, post-construction involves the drying time of the joint concrete, which is estimated as one day. As can be seen from Table 3, off-site 3 DCP requires more time for the whole process due to the longer post-construction phase.