## 4 Human-Centered Knowledge Graph Representation for a Wire Harness Assembly Process
### Wire Harness Assembly-Based Case Study
\begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{3}{c}{**Work sections of the production lines**} \\ \hline Storage & [K1, K2] \\ Buffer & [B1, B2, B3, B4, B5, B6, B7, B8] \\ Crimping stations & [Crimping 1, Crimping 2, Crimping 3, Crimping 4] \\ Assembly stations & [Assembly 1, Assembly 2, Assembly 3, Assembly 4] \\ \hline \multicolumn{3}{c}{Human–machine members and assets} \\ \hline Operators & [O1, O2, O3, O4, O5, O6, O7] \\ Robots & [R1, R2, R3, R4, R5, R6] \\ AGV & [AGV1] \\ Machines & [M1, M2, M3, M4] \\ Tools & [E1, E2, E3, E4, E5] \\ \hline Capabilities & [C1, C3, C6, C7, C8, C9] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The elements of the wire harness assembly lines. Figure 6: The process flow of the wire harness assembly line benchmark. system. Additionally, the distances over which materials are moved are marked with purple numbers. The process flow, illustrated in Figure 6, begins at Storage 1, where the operator known as jumper \(O1\) loads \(AGV1\) (using capability C8) with a batch, which is then transferred by \(AGV1\) to either Crimping station 1 or 3 (using capability C9), where the unloading is performed by operator \(O2\) or \(O5\) into the local buffers \(B1\) or \(B5\). The subsequent steps are identical on both production lines, with the continuation of the process description focusing on Production line 1. As per the production plan, operator \(O2\) carries out crimping-related activities listed in Table A2 that necessitate capability C7. Furthermore, machine \(M1\) is utilized during these crimping activities. Subsequently, operator \(O2\) transfers the workpiece to operator \(O3\) at Assembly station 1 (one-piece-flow). Operator \(O3\) and robot \(R1\) collaborate, carrying out activities related to capabilities \(C1,C3\), and C6. Additionally, tools \(E1\)-\(3\) are employed during the activity steps at Assembly station 1. At the conclusion of the process, operator \(O3\) places the workpiece into buffer \(B2\). Upon the completion of a full batch, the same operator loads \(AGV1\), which transports the batch of cables to the subsequent buffer, \(B3\). Subsequently, robot \(R2\) unloads the buffer and performs activities related to capability C7 and machine \(M2\) at Crimping station 2. Following this, robot \(R2\) transfers the workpiece (one-piece-flow) to operator \(O4\) at the subsequent station, Assembly station 2. At the final workstation of Production line 1, operator \(O4\) and robot \(R3\) collaborate to carry out activities requiring capabilities \(C1,C3\), and C6. At the end of the assembly line, operator \(O4\) places the workpiece into buffer \(B4\). Upon completion of a full batch, the same operator loads \(AGV1\), which delivers the products to their final destination, Storage 2. Furthermore, it is important to mention that this case study also includes different types of sensors, the purpose of which is to make observations about each activity, human, and machine of the production line, as well as to monitor the working conditions. These groups of sensors are camera systems, RTLS, robot-embedded sensor data, machine-embedded sensor data, environmental sensors, and human body sensors. All three categories of workstations are included in this instance focusing on collaborative work. Crimping Station 1 and 3 are characterized as manual workstations, while Crimping Station 2 and 4 are classified as automatic workstations. The research features four collaborative workstations, denoted as Assembly stations 1-4. The specific case study on harness assembly delves into collaboration types 3 and 4. An illustration of concurrent and supportive collaboration is shown in Figure 7. In this simplified scenario, four distinct outcomes are observed, corresponding to the tasks executed by the entities Robot 3 and Operator 4. For instances Result 28 and 31, where both human and robot actors engage in similar activities on the same product, they engage in supportive collaborations aimed at achieving the same assembly result.