## 3 In Situ Measurements and Creation of Current State Models  
In both software solutions, a virtual working environment of an industrial hall with dimensions (10 \(\times\) 13 \(\times\) 8) m was created (Figure 1). Given the capabilities offered by both programs, a comprehensive model of the working environment was created in the simulation environment of the Dialux Evo software. This layout was then imported into the Relux software environment. Based on both technical drawings and in situ measurements, a detailed model of the working environment was constructed in Dialux. This model includes three CNC machines and auxiliary tables (AT1-AT3) used for auxiliary tasks, storage of tools, or intermediate storage for further production. The analyzed working environment was constructed in accordance with the working procedure of the simulation model [40]. To build the model, the first step involved determining the dimensional characteristics of the analyzed space and classifying the space and its application (Figure 2), which ensures compliance with normative requirements. In the created models, the reflectances of objects and materials were set to the same values in both software tools, in accordance with the recommendations established by the ISO/CIE TS 20 012 36 0072 standard [43]. The creation of the lighting system (characteristics of luminaires and their arrangement in the space) was based on the initial in situ measurements. Due to the outdated lighting system, it was not possible to identify precise parameters, and no technical documentation existed. Initial measurements were conducted at three measurement points on the auxiliary tables (designated AT1-AT3). At each measurement point, a series of continuous measurements was performed for 5 min, with data recording intervals of 5 s. Measurements were conducted in accordance with international standards of the International Commission on Illumination using a KIMO LX200 lux meter (Kimo Electronic Pvt Ltd., Mumbai, India) and evaluated with LLX200-specialized software., v1.3.2.0. The following graph (Figure 3) shows the average values  
Figure 1: Industrial hall used for determining the maintenance factor in industrial practice. Figure 2: Initial setup (**a**) and model of the production hall (**b**) in Dialux; importing cad layout (**c**) and model of the production hall (**d**) in Relux. of illuminance and uniformity at points AT1, AT2, and AT3--the monitored areas of the production hall. According to current standards [44], the illuminance level for this type of operation should reach at least 300 k, and up to 500 k in spaces without natural light. The graph clearly shows that the illuminance levels at the monitored points do not meet these minimum values, necessitating the rationalization of the lighting system. Adjustments based on uniformity values are not needed, as all monitored points showed values above 0.6. The necessity of rationalizing the lighting system can also be confirmed by the illuminance measurements over time, as shown in Figure 4. These time-dependent measurements revealed significant fluctuations in illuminance over short periods, primarily due to the outdated and poorly maintained lighting system. Based on the initial measurements, a comprehensive model of the current lighting system was created (Figure 5) to facilitate the subsequent redesign. Three calculation planes were also established, which were analogous to the in situ measurements--AT1, AT2, and AT3. The results obtained from the simulations were then verified against the in situ measurements to facilitate the light redesign in the production hall. The values obtained from the simulations and the deviations from the in situ measurements are presented in Table 1.  
From the conducted comparison and its graphical interpretation (Figure 6), the accuracy of the constructed models can be confirmed.