# Advancements in Data Analysis for the Work-Sampling Method
## 5 Case Study  
In the selected medium-sized metalworking company (with make-to-order production), we carried out the necessary observations as part of the work-sampling project. We selected a machining company (turning operations) with 17 workplaces (7 types of machines). The analyst's observation route is shown in Figure 3. Each visit was carried out in a random direction: clockwise or anti-clockwise. Two rounds per hour were possible (only one in the hour in which there was a 30 min break), so that we collected 255 observations in one shift (8 h: 7 \(\times\) 2 + 1 = 15 observations per workplace, 17 workplaces). Figure 3: Analyst’s observation route in the work-sampling study. Figure 2: Steps of the work-sampling method with the addition of correlation analysis (in red). Through pilot recordings, we found that over 4000 observations were necessary and identified 23 operator activities:  
\[ \begin{array}{l}\text{Machining}\\ \text{Clamping/unclamping the workpiece}\\ \text{Dimensional control}\\ \text{Tool movement in the machining position}\\ \text{Clamping/unclamping of tool}\\ \text{Workstation set-up}\\ \text{Study of working instructions}\\ \text{Conversation about tasks}\\ \text{Tool set-up}\\ \text{Collecting/returning of tools}\\ \text{Cleaning the machine}\\ \text{Personal needs (toilet, washing, etc.)}\\ \text{Annotation of work results}\\ \text{Handover of work}\\ \text{Waiting for transport}\\ \text{Waiting for documentation}\\ \text{Machine failure}\\ \text{Absence from company}\\ \text{Business meeting}\\ \text{Power outage}\\ \text{Repair of defects}\\ \text{Private conversation}\\ \text{Private absence from the workplace}\\ \end{array} \]  
During the main recording, 4131 observations were collected. We used the Drigus Multidata recording device shown in Figure 4. We observed labor in two shifts, from Monday to Friday. The results are summarized in Tables 2 and 3. The results for weekdays and shifts are not included. Figure 4: Drigus Multidata recording device. \begin{table}
\begin{tabular}{l c c} \hline \hline
**Activity** & **Number of Observations** & **Portion (\%)** \\ \hline
1. Machining & 2129 & 51.54 \\
2. Clamping/unclamping the workpiece & 176 & 4.26 \\
3. Dimensional control & 153 & 3.70 \\
4. Tool movement in the machining position & 19 & 0.46 \\
5. Clamping/unclamping of the tool & 27 & 0.65 \\ _Productive work_ & 2504 & 60.61 \\
6. Workstation set-up & 34 & 0.82 \\
7. Study of working instructions & 49 & 1.19 \\
8. Conversation about tasks & 43 & 1.04 \\
9. Tool set-up & 201 & 4.87 \\
10. Collecting/returning of tools & 51 & 1.23 \\
11. Cleaning the machine & 114 & 2.76 \\
12. Personal needs (toilet, washing, etc.) & 214 & 5.18 \\
13. Annotation of work results & 38 & 0.92 \\
14. Handover of work & 6 & 0.15 \\
14. Planetary losses & 750 & 18.16 \\
15. Waiting for transport & 11 & 0.27 \\
16. Waiting for documentation & 0 & 0 \\
17. Machine failure & 0 & 0 \\
18. Absence from company & 250 & 6.05 \\
19. Business meeting & 37 & 0.90 \\
20. Power outage & 0 & 0 \\
21. Repair of defects & 2 & 0.05 \\ _Unplanned losses_ & 300 & 7.26 \\
22. Private conversation & 377 & 9.13 \\
23. Private absence from the workplace & 200 & 4.84 \\ _Indiscipline_ & 577 & 13.97 \\
**Total** & **4131** & **100.00** \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The proportion of the workday spent on each activity.