## 3 Results
### Evaluation  
The deployment at the first practical case, TRI, yielded a valuable opportunity to evaluate the acceptance of the system. The Technology Acceptance Model (TAM) [67] is used as both survey and outline for the interviews. The model includes twelve questions, divided into two sections for usefulness and ease of use. Importantly, the questions aim to determine whether the user prefers to use the new technology, compared to the previous way of working. All twelve questions are measured on a Likert scale of one to seven, ranging from extremely likely to extremely unlikely. Figure 15 shows the 7-point Likert scale for the questions. Figure 14: Duration of fetch and return tasks, as performed by different agents. Figure 13: Duration of the assembly and disassembly tasks as performed by different agents. Nineteen process participants at TRI were interviewed, immediately after the person interacted with the HORSE System prototype. The nineteen people can be broken into the following categories:  
* Two experienced tooling engineers;
* Two intermediate tooling engineers (fully trained but not yet experienced);
* Thirteen inexperienced operators;
* Thirteen supervisors. The 19 surveys and interviews generated significant data to be used for evaluation. Table 4 shows the 12 statements posed to the interviewees and the average rating as reported by the interviewees. The system, as named in the survey statements, refers to the HORSE System, i.e., the collection of HORSE developments involved in the pilot case scenario including the process management and augmented reality solution. As an overview, the system rated favourably, with only two statements garnering a slightly unfavourable rating. With 4 representing a completely neutral point on the scale of 1 to 7, none of the questions had a below average overall response. To give some more insight into the range of responses, Figure 16 shows the average ratings and standard deviations for all twelve questions. The participants were highly enthusiastic of the usefulness of the system. This optimism is often attributed to the procedural nature of the process-centric approach. They acknowledged the value of having a system that encourages disciplined process execution. This is even more important for inexperienced operators, who can be trained faster to participate in complex processes. Apart from increased discipline, some participants also appreciate the lessened mental burden. The augmented reality presents the relevant information, as encoded in the process model, to perform a task and the process automatically moves to the next task, thus making it easier for an operator to follow instructions and perform the work. \begin{table}
\begin{tabular}{l l l} \hline \hline
**Nr** & **Statement** & **Average Rating** \\ \hline
1 & Using the system in my job would enable me to accomplish tasks more quickly. & 2.32 \\
2 & Using the system would improve my job performance. & 2.26 \\
3 & Using the system in my job would increase my productivity. & 2.37 \\
4 & Using the system would enhance my effectiveness on the job. & 2.21 \\
5 & Using the system would make it easier to do my job. & 1.79 \\
6 & I would find the system useful in my job. & 2.16 \\
7 & Learning to operate the system would be easy for me. & 1.42 \\
8 & I would find it easy to get the system to do what I want it to do. & 3.53 \\
9 & My interaction with the system would be clear and understandable. & 1.84 \\
10 & I would find the system to be flexible to interact with. & 3.58 \\
11 & It would be easy for me to become skilful at using the system. & 1.68 \\
12 & I would find the system easy to use. & 1.79 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Questions asked during interviews with average ratings by interviewees. Figure 15: 7-point Likert scale for usefulness and ease of use (1 = extremely likely... 7 = extremely unlikely). A common realisation amongst participants was that they never noticed the mobile robot.