# Augmented Reality in a Lean Workplace at Smart Factories: A Case Study
## 6 Analysis and Discussion  
### Identified Improvements Potential  
It is fundamental to assess the current risks in workspaces and the possible effects of AR technology implementation and acceptance. To do this, a questionnaire was designed and administered to collect worker's opinions on the implementation of these solutions in their workspaces. This questionnaire aims to analyse and evaluate the potential for improvement that comes with the implementation of the AR solutions presented in the previous section, in order to reduce risks and improve ergonomic conditions at workplaces.  
The designed questionnaire was based on the Nordic Musculoskeletal Questionnaire (NMQ) [83], which consists in a standardized methodology that allows the comparison between complaints regarding different parts of the body [84]. In the context of this study, the NMQ has been used as a structured interview, following a systematic approach where logistic workers are asked the same predetermined questions in the same order. Moreover, each question is rated following a standardized scoring system.  
The questionnaire was applied to workers from the most critical logistic areas, defined in step 1.1 of the proposed methodology:  
1. Incoming and raw materials warehouse;
2. Internal logistics.  
Furthermore, within the abovementioned critical areas, special attention has been given to the tasks with the highest criticality regarding the HSE risk assessment carried out during step 2.3. Thus, workers that perform logistic tasks that comprise risk factors categorised with medium, high or extreme criticality during this assessment have participated in the questionnaire in order to evaluate the mitigation measures proposed during step 2.5 of the developed methodology. These critical tasks are presented in Table 6.  
Moreover, during phase 3 of the RAES-Log methodology, lifting and lowering loads operations within the incoming area and picking operations within supermarkets have been analysed in order to assess the risk factors regarding ergonomic conditions. Special attention was given to the workers performing these two operations, and they were invited to take part in the study to evaluate the AR solutions proposed in step 3.4 of the methodology.  
From a population of 188 workers within the two most critical logistic areas, a sample of 50 workers has been defined to make inferences on the population. This calculation considers 10% of the margin of error, 90% of the confidence level and 50% of the response distribution. Therefore, 50 workers, who participated voluntarily, were interviewed during the course of their workday while doing their tasks. The questions were posed in the form of an interview and noted down, with explanations given as needed.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Logistic Area** & **Tasks** \\ \hline Incoming and raw materials warehouse & Incoming Warehousing \\ \hline \hline \end{tabular}
\begin{tabular}{c c} \hline \hline
**Logistic Area** & **Tasks** \\ \hline Incoming and raw materials warehouse & Incoming Warehousing \\ \hline \hline \end{tabular}
\begin{tabular}{c c} \hline \hline
**Repacking** & **Tasks** \\ \hline Internal logistics & Final and SMD assembly supermarkets \\ Lines supply \\ \hline \hline \end{tabular}
\end{table}
Table 6: Logistic tasks with highest criticality levels regarding HSE risk factors [59].  
Therefore, this study pursued four specific objectives:  
1. Characterise the workers' sample with demographic data;
2. Analyse wellbeing and discomfort of workers;
3. Assess physical exertion perceived by the workers and identify the most demanding tasks;
4. Assess proposed AR solutions acceptance indicators based on the workers' opinion.  
For this purpose, the results of each category are detailed in the next section. The full questionnaire is presented in Appendix A--Questionnaire.