## 5 Evaluation Phase According to Design Science Research
### Assessing Utility and Applicability  
The applicability with respect to DSR has been proven through successful practice in the pilot project. Experts from the industry partner who applied this approach had no or little transition problems following the new process and making use of the artefacts. On the one hand, this was confirmed by the interviews of experts involved. On the other hand, the findings show that the time required to prepare the bid drawing using the BIM-based approach was identical to the previous CAD approach, although this was a first experiment. With increasing experience in handling the BIM authoring tool and the artefacts, an even easier handling in the course of learning effect and thus a higher applicability can be expected. In terms of utility with respect to DSR, Table 2 shows that the BIM-based approach provides for benefits in the time required to allocate the physical containers. This makes a direct application of the new BIM process for the industry partner recommendable, since its utility is characterized \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sub-Process** & **Current Process** & **BIM-Based** & **Time Savings [\%]** \\ \hline Creation of bid drawing & 2 h & 2 h & 0 \\ Container selection and & 3 h & 0.5 h & 83.3 \\ ID assignment & 2 h & 0.1 h & 95.8 \\ Creation of 2D plans & 2 h & 0.1 h & 95.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of process durations: Current process vs. BIM-based. \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Time Needed According to Applied Approach** \\ \hline
**Bid Estimation Item** & **Current Process** & **BIM-based** \\ \hline Panel modifications & 2 weeks & 2.5 weeks \\ Container installation & 5 days & 7 days \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of assembly times: Current process vs. BIM-based. by substantial time savings. On the other hand, Table 3 indicates that the automated calculation of the time required for panel modifications and container installation is greater than the traditionally estimated time. Therefore, the BIM-based bid estimation could lead to less economical bids, and thus brings with it an increased risk of being outbid by competitors in future tenders. This mismatch is due to the absence of an accurate effort function for panel modifications, which takes into account non-linearities when panels are modified in a continuous fashion during the container preparation phase rather than constituting discrete events. In order to fully reap the benefits of an accurate BIM-based calculation, it is therefore necessary to formulate a proper effort function for panel modification, since the total effort is not a simple linear proportionality of the number of panels to be modified. Rather, the situation is that, depending on the total number of containers, a minimum effort is required if at least one panel must be modified on the container in question. However, there is a difference in terms of effort per panel whether, e.g., all five or six panels on one wall must be modified, or just one. In this case, the effort per panel decreases the more panels that need to be modified. Hence, to increase the utility of the suggested approach, an effort function must be formulated which accounts for non-linear phenomena and interactions between effort predictors. For that purpose, we conducted interviews with experts from the industry partner, asking them to estimate the effort for panel modification in different hypothetical project scenarios according to their experience. This data set given in Table 4.  
Given this data set, we performed statistical analyses based on a response surface methodology (RSM) approach. RSM is a collection of statistical and mathematical methods to investigate the impact of several predicting variables (predictors) on one or more responding variables (response) [33]. Depending on the dominant container size, the statistical analyses led to different regression equations providing for a response, which is the effort of panel modifications in days.