# Poka Yoke in Smart Production Systems with Pick-to-Light Implementation to Increase Efficiency
## 4 Results
### Test before Application of PTL  
With the constant improvement in produced parts, components or sometimes entire objects, the number of different variants of their construction also increases. This emphasises the number of elements that must be in the workplace in a given situation. Individual components are usually prepared in containers or complete sets, and the worker chooses the ones he needs based on the printed specification or assembly procedure. The employee entrusted with the assembly of the model part has trays with various components placed on the work table, representing the workplace. Based on the prepared assembly procedure, he prepares the individual containers and starts assembling the model part.  
This classic approach to assembly activities carries several negatives. The most important ones can be ranked:  
* The length of the assembly-procedure training unnecessarily extends the start of the assembly process;
* Frequent viewing of the assembly procedure--another unnecessary waste of time;
* The constant pressure exerted by the moderator causes inattention and tension, resulting in errors and inappropriate pieces;
* The simulation of such a situation arouses unnecessary nervousness and uncertainty in the student;
* The workplace becomes uncomfortable and less and less psychologically bearable.  
As mentioned, the test was conducted on a selected sample of 30 employees of an SME company. We gradually measured individual preparatory times and assembly operations, which we recorded in a Table 2. The first step was the components and individual tools needed for assembly. This operation ranged from 20-30 s, with an average workplace preparation time of 24.7 s per production batch of 10 pieces. The second operation was the initial employee training on safety and health protection. These operations lasted 5-20 s, with an average training time of 11.2 s. The third operation studies the technological procedure printed in A4 format (see Figure 6). The initial study took place in the range of 24-37 s, with an average time of 30 s. Subsequently, the component was assembled according to the manual described in Section 3.3. Assembly consisting of six steps was in the range of 56-70 s, while the average assembly time of one component was 63.83 s. Each employee repeated the assembly 10 times, which were recorded in a table. Subsequently, an optical check of connection and functionality took place. It is a non-time-consuming test that lasted 4.5 s on average. The last operation was the final storage of the assembled extruders in the transport box. This operation lasted from 4 to 9 s, with an average time of 6.43 s.  
\begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline
**Operation/Worker (s)** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **30** & **Average Time (s)** \\ \hline Component and tool preparation & 20 & 22 & 21 & 30 & 22 & 25 & 24 & 26 &... & 26 & 24.7 \\ \hline Training & 5 & 10 & 12 & 10 & 13 & 11 & 5 & 6 &... & 7 & 11.16667 \\ \hline Studying the procedure & 30 & 27 & 29 & 25 & 35 & 32 & 26 & 24 &... & 26 & 29.66667 \\ \hline Assembly of one part & 65 & 65 & 69 & 62 & 63 & 65 & 68 & 70 &... & 61 & 63.83333 \\ \hline Assembly of the production batch (10 pcs.) & 726 & 736 & 820 & 862 & 763 & 734 & 792 & 812 &... & 826 & 789.7667 \\ \hline Connection check & 5 & 4 & 6 & 3 & 5 & 6 & 4 & 6 &... & 5 & 4.433333 \\ \hline Storage in a box & 4 & 4 & 6 & 4 & 6 & 8 & 4 & 9 &... & 5 & 6.433333 \\ \hline Total assembly time 1 pc. & 129 & 132 & 143 & 134 & 144 & 147 & 131 & 141 &... & 130 & 140.2333 \\ \hline Total assembly time 10 pcs. & 871 & 875 & 1002 & 997 & 943 & 942 & 927 & 1018 &... & 985 & 963.9667 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Time measurement before the PTL introduction.