# Enhancing Production Efficiency Through Digital Twin Simulation Scheduling
## 2 Materials and Methods  
For the implementation of a digital twin within the production scheduling process in a custom production environment, it is necessary to perform a detailed analysis of the current state of data collection in the company. This step involves identifying any relevant data that are either not currently being collected or are being collected in an inefficient manner. Based on the findings from this analysis, the most suitable technology for data collection is then selected, which enables the transfer of information in real time from the sensory devices that are fitted to the individual monitored elements of the environment. In this case study, a real-time location system (RTLS), which is based on ultra-wideband (UWB) technology, is used. A schematic representation of the data collection process is shown in Figure 2. This combination of technologies is chosen due to their high accuracy and ability to resist electromagnetic interference, which could affect the performance of other communication technologies. Individual UWB tags are placed on all monitored objects within the production process, including operators, machines, and logistics equipment. These devices communicate with stationary anchors (RTLS anchors) located throughout the production area, which then ensure the transfer of data to a central server. The individual UWB tags are divided into the following categories. * Personal UWB tag--This is characterized by a small size and weight; it is suitable for the monitoring of operators and smaller elements. It includes a 600 mAh non-rechargeable battery. * Tag for logistics means--This includes a rechargeable battery, a USB interface for charging and configuration, and the ability to configure wirelessly. It is designed for the tracking of logistics equipment and larger elements. * UWB tags for machinery--This does not contain a battery and is wired to the machinery. It is used to read and send all the necessary data collected from the device. To transmit these data between individual devices and a central database, a specific communication protocol based on standards such as ODBC is developed. This transmission mechanism ensures efficient and secure communication between different systems and  
Figure 2: Method of online data collection from the production system [16; 33]. guarantees the proper functionality of the entire digital twin system. This system uses the currently collected data to optimize production plans and adjust them flexibly in response to emerging changes in production. To verify the correctness of the implemented system for the creation of production schedules, simulation experiments are carried out, which compare the expected results with real data collected during operation. This process is used to validate the planning module and its ability to predict and effectively manage production processes. The module for the generation of variants of production schedules, together with the parametric simulation model, forms the core of the scheduling system. Within the schedule generation module, tools are applied to sort production orders according to certain priority rules or a combination of them. After the arrival of a request for scheduling or the adaptation of the schedule for various reasons (arrival of new orders, change in order priority, deviation from the plan, etc. ), a simulation run is started, where the list of orders will be updated using the control method and their status will be identified. An order can already be sorted, in a pending state or a work-in-progress state, and executed. Executed orders will be deleted from the list, orders in a work-in-progress state will have to be processed, and new and unfinished orders will undergo a sorting evaluation and will be reordered for release into production. The logic of the order prioritization system is shown in the diagram below (Figure 3). The value of the order priority factor is influenced by several factors, namely  
Figure 3: Order prioritization flowchart.