## 1 Introduction  
Modern manufacturing industries face a range of challenges arising from the dynamic development of technology, global competition, and increasing customer demands for quality, efficiency, and flexibility. Manufacturing companies must continuously adapt to changing market conditions by implementing advanced technologies and improving their processes to ensure high product quality while simultaneously reducing production costs and lead times. In this context, simulation tools play a particularly important role, as they enable comprehensive modeling, analysis, and optimization of production processes, thereby supporting informed strategic and operational decision-making.  
Simulation is also a key enabler of smart factory implementations within Industry 4.0 frameworks, supporting connectivity, automation, and intelligent decision-making [1].  
Production process simulation is a tool that allows real-world working conditions [2] to be replicated in a virtual environment, enabling the testing of various operating scenarios without interfering with the actual process. The use of advanced software, such as FlexSim,allows for the analysis of material flow, identification of bottlenecks, evaluation of machine and resource performance, and assessment of how changes affect the entire production system [3,4]. In the context of electronics manufacturing where precision and technological complexity are critical, simulation becomes an indispensable element that supports the development and refinement of processes [5].  
Moreover, simulation contributes to the design of sustainable manufacturing systems by enabling detailed evaluation of environmental and operational impacts [6].  
One of the most demanding stages in the manufacturing of electronic assemblies is the selective soldering process, which requires precise joining of specific points on printed circuit boards. Selective soldering enables the creation of durable and reliable solder joints, but it requires advanced planning and accurate synchronization of resources and operations. Introducing a simulation tool makes it possible to analyze critical aspects of the process, such as cycle time, operation sequence, resource availability, and material flow, thereby improving the efficiency of the entire system.  
The aim of this study was to develop a simulation model of the selective soldering process for a technology company in Poland. The work focuses on creating a tool to support the analysis and improvement of this key process while also examining potential execution scenarios. The results of the study serve two main objectives. First, they provide detailed insights into opportunities for improving the efficiency of the selective soldering process at the company, leading to better resource utilization and reduced production lead time. Second, the project aims to develop a universal tool that can be used in future efforts to analyze and optimize other production processes within the company. As such, the simulation model not only supports the company's current operational needs but also serves as a foundation for its long-term development strategy and adaptation to future technological and market challenges.  
Upon reviewing the literature related to the topic under investigation, we observed that simulations are most commonly conducted for specific, case-based scenarios. In such studies, the majority of process parameters are incorporated into the simulation model as they are encountered in real-world conditions. Consequently, our focus was directed toward the development of a universal and adaptable tool. As a result of this effort, a flexible framework was created, capable of handling various process durations and allowing for easy reconfiguration of equipment within the production line.