## 1 Introduction  
Lean manufacturing as a philosophy and methodology is used to manage and optimize production processes. It puts emphasis on eliminating waste, improving production efficiency and effectiveness, and increasing product quality and customer satisfaction. The concept originated in Japan in the 1950s and is also known as the Toyota Production System (TPS) because it was developed by Toyota. The main principles of lean manufacturing are as follows [1; 2; 3; 4; 5]:  
* Identify value from the customer's perspective: determine what customers value and what they are willing to pay for. * Map the value stream: map the steps involved in producing a product or service and identify areas where waste can be eliminated. * Create flow: create a continuous flow of work through the system, reducing lead times and work in progress. * Establish pull: only produce what is needed when it is needed based on customer demand. * Seek perfection: continuously improve the system by eliminating waste and improving efficiency. Below are the most commonly used lean manufacturing tools that help achieve the assumed goals [6; 7; 8; 9; 10]:  
* SS(used to create an optimal workplace, and its name is an acronym of five Japanese words: 1. Seiri (selection)--we separate all materials (instructions, tools) from each other at the workplace and remove unnecessary things. * Seiton (organization)--we designate and mark tools and their parts. * Seiso (cleaning)--removing dirt, laying, cleaning, and renewing the workplace. * Seiketsu (standardization)--constantly keeping the workplace in order so it remains clean and tidy (here we smoothly move on to the next tool). * Shitsuke (self-discipline)--habits and habits necessary to comply with the implemented improvement solutions. * Kaizen: means continuous improvement and consists of the continuous introduction of changes and improvements with the help of small steps. * Kanban: allows you to control production by events occurring directly in production. * TPM, i.e., Total Productive Maintenance: this Comprehensive Productivity Maintenance enables the activation of all employees and machines to maximize the total efficiency of production resources. * SMED, i.e., Single Minute Exchange of Die: literally translated as a one-minute exchange of a mold or tool that sets the goal of reducing changeover time to 10 min or less. * VSA, or Value Stream Analysis: value stream mapping, as the main lean tool, enables visualization of information flow and the manufacturing process for selected products. * Six Sigma: used to reduce costs and improve quality through the use of statistical tools. * Poka-yoke: used to prevent errors from appearing through technical solutions, etc. One of the key principles of lean manufacturing, allowing for the efficient implementation of lean tools, is the standardization of production processes, which consists of setting standards of conduct that allow for the expected results to be achieved in a repeatable and effective manner. The standardization of production processes comprises the creation of unambiguous, defined procedures that are used at every stage of production. Within lean manufacturing, the standardization process is often used, involving the use of tools such as Standard Work and Standard Operating Procedures (SOPs). Standard Work is the description of an ideal production process including the time needed to complete individual tasks by employees, while SOPs are detailed instructions for the production process [8; 9; 10; 11]. The standardization of production processes is therefore aimed at increasing the efficiency of processes, reducing errors and deviations, and unifying the final results. In the context of lean manufacturing, standardization is extremely important for the smooth functioning of the tools used in the lean manufacturing methodology and plays an important role in eliminating waste and improving efficiency.