## 2 Literature Review
It is also one of the most difficult, as productivity means finding a balance between a variety of factors, few of which are easily defined or easily measurable [26]. According to [27; 28; 29], the company does not focus only on reducing costs, but on reducing time consumed in individual operations, while creating real and lasting market advantages. Based on [30], companies find that by reducing the duration of individual operations, they reduce costs without further effort. Productivity could be characterized as a measure of the correctness of the use of resources in the production of a product. The basic factors that can be used to analyze productivity well and look for potential productivity improvements are:  
1. Utilization rate (U), which corresponds to the actual value of resources that are transformed into a product. To increase productivity, it is necessary to know the factors that contribute to the indicator. It is mainly the use of inputs, especially the use of working hours of the worker, usable time for machinery, and usability of the acquired material. Working time is the time for which the worker is paid. Waiting is caused, for example, by unnecessary breaks, but also by the organization of work. Working time consists of excess work that the worker should not perform in optimal condition (repairs of failures, bad technological procedure, etc.) and productive work. The role of management is to increase the share of productive work. The distribution of usable working time is shown in Figure 1.  
Figure 1: Usable working time structure. The usable work fund of the employee relates to his behavior. Losses are often the same as using labor, but larger losses are due to poor planning [31]. When evaluating the utilization of the production capacity of production lines and evaluating their performance, the following are considered:  
1. Performance measure (P), which describes the speed and pace of transformation. The rate of performance is the speed and pace of work, and if the speed is higher, productivity will increase. This factor is mainly influenced by machines and workers [32]. 2. Quality measure (Q), which records the accuracy and quality of the transformation. The level of quality is measured through various activities, which are summarized in the issue of \"quality management\", which includes checking the conformity or non-conformity of products with defined patterns [32]. 3. Methods level (M) presents the methods used in the transformation [33]. Proper use of time leads to good performance and products that are of good quality, but if work is not done using productive working methods, the resulting productivity will be significantly lower than that which could be achieved [32]. To express the effect of these factors affecting productivity, it is appropriate to use a mathematical relationship that is the product of them all. Total Productivity Index (TIP) is equal to:  
\[\text{TIP}=\text{U}\cdot\text{P}\cdot\text{Q}\cdot\text{M} \tag{1}\]  
It follows from this formula that when increasing productivity, no factor can be forgotten, because even an exceptional improvement of two factors will not attain the highest productivity. The goal of all lean manufacturing methods and tools is to eliminate, or at least reduce, waste. In connection with the elimination of losses of the production process, three basic types of tools are used according to the waste management phase they are used in: (a) methods and tools in the analysis phase--standard analytical tools aimed at identifying waste in the process, (b) methods and tools in the phase elimination--aimed at achieving improvement of the current state, (c) methods and tools in the functionality phase--verification of the functionality of the proposed solution and maintaining a new state [34]. Individual methods and tools for loss elimination can be focused on the analysis and measurement of work, balancing operations, standardization and visualization, ergonomics and economics of movements or modeling and simulation of processes.