## 2 Materials and Methods--Main Topics in the Field of Pre-Research
### Logistics Audits with a Focus on Internal Logistics  
Internal logistics can be described as a discipline that deals with logistics chains within an industrial plant or between plants within a single company [29; 30; 31]. Internal logistics covers planning, implementation, control and efficient flow and storage of materials, semi-finished and finished products in a production environment [32; 33]. The primary operational functions of internal logistics are handling, receipt and storage, internal transport, picking and packaging [28]. Internal logistics is fully responsible for the internal flow of material and information, thus connecting internal systems, from the entrance warehouse area (goods receipt, warehousing), through internal handling and the supply of production and assembly workplaces to goods dispatch (picking) [34]. A logistics audit is a method for the comprehensive and independent diagnostics of the functionality of the company's logistics system [35; 36]. It includes the determination of a strategy and tactics and a plan for eliminating deficiencies and subsequent improvement of the logistics system [37; 38]. A total of three methodologies for logistics audits used in industrial enterprises were analysed--methodologies according to the Chamber of Logistics Auditors (CHLA), VDA 6.3 and MMOG/LE. For the analysis of the logistics audit methodologies, two companies in the automotive industry that use these methodologies were visited in person and special workshops and consultations were conducted. The methodologies of the logistic audits were analysed in detail and Table 1 shows the main attributes of each methodology. The main areas for evaluation are essentially the same, they only differ in their scope. Other analysed attributes are the advantages and disadvantages of each methodology. It is important to focus on a key attribute in the field of logistics as a subject of evaluation according to the audits, where the main parameters sought were specifically the processes of internal logistics (not external logistics within the supply chain). VDA 6.3 and MMOG/LE are used mainly in the automotive field, while the CHLA methodology is more universal. The methodologies also have their own assessment systems for output evaluation, and mainly use numerical point evaluation of the parameters. The main attributes used for the final evaluation are listed in Table 2. One of the most relevant aspects for research is the definition of areas in internal logistics. In addition to the key attribute of internal logistics evaluation, the Industry 4.0 factor is also important. The potential of internal logistics evaluation corresponding to Industry 4.0, i.e., integration of this concept into audit methodologies, was analysed. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Methodology by Source** & **Areas of Evaluation** & **Advantages of Methodology** & **Disadvantages of the Methodology** & **Area of Use** & **Evaluation Method** \\ \hline \multirow{4}{*}{CHLA [37; 38] and support processes} & Management, production, quality, logistics & Logistically detailed Revealing potential Proposal of activities & Continuity Duration & \multirow{2}{*}{Universal} & \multirow{2}{*}{Hard methodology + subjective evaluation} \\  & Management, production, quality, logistics & Volume of all departments & Not detailed features Failure to reveal Patient & Automotive & Hard methodology \\ \hline MMOG/LE [43; 44; 45] & Management, quality, logistics & Logistically detailed Revealing potential Efficiency selection & Need for support files Traceability & Automotive & Hard methodology \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Analysed attributes of the logistics audit methods. Overall assessment of this topic: The main purpose of the analyses related to the logistics audit methodologies was to define the area of internal logistics.