## 5 Production Impacts of Exoskeletons in Manufacturing, Especially \"Time Management\"
### Impact from Time-Management Perspective  
Feasibility tests with exoskeletons in the automotive industry lead to the idea that time management is affected during work execution. Scientific work proves this assumption as follows: In [24], an increase in task time from 8 to 9 s was observed during ergonomic investigations; [31] even reports an average productivity increase of 40% for painting and 86% in welding operations; and [32] shows a tripling of the holding capacity (from 3.2 to 9.7 min) through the exoskeleton. Productivity in this context means less time for the same task, but the exoskeleton technology is not to be used as a performance-enhancing tool. However, their benefits can be argued based on ergonomic improvements as an additional side effect. In a further investigation of the applicability of passive upper-limb exoskeletons for the automotive industry [33], several experiments proved that the defined \"precision index\" and quality increased by 16.7%. This has a relevant impact on time management. In most existing studies, the focus is on ergonomic evaluation, while only a few studies are for time-management purposes.  
In the context of exoskeletons integrated into workplaces, the difference between diverse types of the time impacts (Figure 6) has to be considered. The three types are (1) setup times, (2) task-execution impacts and (3) process-related impacts. If exoskeletons are mandatory [34] as required manufacturing tools or employed as prevention measures for the execution of processes, the impact regarding the time management has to be considered in the process planning. In the case of optional use of exoskeletons, these factors of impact are important as well. The focus relies mainly on the integration of this technology in serial production. Additional factors like the initial adjustments, training, briefing and maintenance work are not considered.  
Figure 6: Three categories of time-management impacts for exoskeleton integration [4].  
Setup times_ for exoskeletons in the workplace, can not be avoided. In this phase, there are considered factors which lead to time loss. Due to this reason, the setup times should be decreased (in the interests of user acceptance as well). Wear/unwear tasks, as well as transit times, are frequent examples. Under some circumstances, it is conceivable to use the exoskeleton just for certain tasks or during certain periods of time and not to wear it during the whole process. This creates the so-called \"hybrid assembly processes\", which are a combination of manual and semiautomated work tasks.  
Task-execution impacts are time-related changes due to the integration of exoskeletons into the original process. Once they are introduced, the performance of a certain task is then either slower or faster. The main reasons for performance slowdowns are restrictions of motion [35; 36]. By using exoskeletons for better precision [33] and high flexibility, faster movements are possible as well.  
Process-related impacts are characterized by the fact that these processes are highly influenced by the integration of exoskeletons. These impacts are connected to rescheduling or emerged abilities due to the use of the device and therefore have a positive impact on time management. Additionally, the embedding of support brackets could optimize gripping processes because of shorter distances (up to a third hand). Likewise, new abilities could be made possible through an additional free hand that was used for support which is now provided by the exoskeleton.