# A Method for Modelling Business-Critical Architecture Decisions in Engineer-to-Order Companies
## 4 Results
### Case Study Results
#### 4.2.3 Critical Fluid-Handling System Architecture Decisions Based on the CAM Method  
In the last part of the case study, the company explored solutions that would decouple and clarify the dependencies between the equipment design and the affected parts of the value chain. The final proposal is shown in Figure 5. The proposal was chosen based on its potential impact on cost and lead time. The figure shows a tweaked design of the fluid-handling system that has the same variety in project requirements but that significantly reduces the impacts of design variance.  
As seen in Figure 5, the first change to the system architecture is the addition of a shared steel frame on which the equipment is mounted. First, this simplifies the interface towards civil engineering. Even if the sub-systems are moved around on the frame, the load points will remain the same and, therefore, will not affect the steel structure. The extra weight of the added frame only slightly increases the cost of the steel structure. This cost is far outweighed by the mitigation of the two-to-three-week change order. The commissioning process has the added benefit of having the storage and dosing equipment mounted on the same frame. Having the equipment assembled in its final layout in the workshop allows the company to run wiring to the instrumentation and connect it to  
\begin{table}
\begin{tabular}{l l} \hline
**Histor Architecture Design Variance** & **Critical Impact on Cost and Lead Time** \\ \hline Optional items not considered in standard layout & Incorrect and late inputs to the civil department \\ \(\Rightarrow\) new placement of high-load items & result in being unable to start civil engineering early \\  & and having to redo structural engineering often. The \\  & average change order impact was 2–3 weeks. \\ \hline Frame construction of systems with high & 78\% of commissioning steps are carried out on-site, \\ instrumentation complexity is optimised for layout & while only 22\% are carried out in the workshop. This \\ flexibility and not commissioning & results in increased travel costs and longer \\ \hline  & Late layout alignment implies that there is not time \\  & for routing piping in CAD, leading to routing and \\ Optional items not considered in standard layout & fabrication being carried out on-site. This results in \\ \(\Rightarrow\) new placement of systems with high & increased installation costs and time by a factor of \\ piping complexity & 2-3. It has also been shown to result in poorer \\  & fabrication quality due to sourcing unknown \\  & contractors locally. \\ \hline \end{tabular}
\end{table}
Table 3: As-is scenario: historic architecture design variance and its impact on cross-functional and cross-value-chain activities.  
the electrical cabinet. This, in turn, enables the company to run many more tests in the workshop before installing the equipment on-site. Ultimately, this gives the company the potential to reduce the number of commissioning steps carried out on-site.  
The second architecture decision is to reserve space for the optional dosing unit from Project B. Project A could be made slightly cheaper by not reserving the space. However, by reserving the space for the unit, the layout interface to the neighbouring units is clarified. This means that the placement of the pipe rack units can be standardised. Having the pipe rack units placed on the right side of the frame allows the piping to exit the room in the  
Figure 5: To-be scenario for fluid-handling equipment illustrated with the CAM method.  
same place in both projects. Therefore, the subsequent pipe routing can be the same across projects. Standard pipe routing allows for pre-fabricating, which saves critical time and on-site construction work costs.