## 2 Machinery Risk Assessment Methodology
### Risk Assessment Methods  
Description of the area, steps of the risk assessment, what suitable methods should be used for what particular purpose (system), is a very extensive issue. This is where mistakes regarding the ideas of risk assessment arise. For example, there are methods that are sufficient for enabling a risk assessment of the mechanical hazards of a sharp machine edge, however, the methods for a risk assessment of a hazardous substance leak (e.g., gas) from a high-pressure pipeline, including its initiation and elements such as \"jet fire\" type are completely different [31]. Each system that requires a risk assessment for either legislative or other reasons has certain recommended methods and procedures that accurately describe its individual application, scenarios, and potential causality [32]) for a hazardous event that may lead to damage (e.g., to life, health, property, environment, etc.). There is a difference in the risk assessment of simple machinery and the risk assessment of a potential explosion in a paint shop or a serious industrial accident of an ammonia leak from a tank. Scenarios involving  
Figure 1: Simplified procedure for machinery risk assessment/risk control (inspired by ISO 12100:2010). a burning building in a built-up area are described differently than scenarios involving a blast-furnace gas leak in an industrial plant. For this reason, the application of measures relates mainly to ensuring reliable and safe technical conditions that prevent the origination of a hazardous event (e.g., prevention of a leak by preventive maintenance), i.e., the so-called preventive measures [33; 34; 35; 36; 37]. To reduce hazard consequences, tools aimed at reducing the extent of the damage after a hazardous event (e.g., sprinklers, extinguishers, alarms, etc.) i.e., the so-called reactive measures, are applied. The simplest methods often applied in practice at the level of machinery risk assessment and the work activities incorporated into the risk assessment are called the \"risk matrix\" [25; 26; 32; 34; 37; 38]. It could be said that it is a framework method that enables the identification of hazardous properties and hazards that may result from them, an assessment of the risks and their evaluation according to the \"own\" rules of the reviewer (e.g., the organization or its management) considering the determined acceptance rate. The basis of this method is following the aforementioned risk assessment algorithm (Figure 1). The harmonized standards for machinery construction EN ISO 12100 [19] stem from the assumption that the construction in question may contain certain hazardous properties concerning its future use: sharp edges, electric parts, thermal sources, ionizing radiation sources, worn parts, liquids, dust, etc. For this reason, to make easier the identification (to ISO 12100 standards) of hazardous situations that may arise during the performance of a given activity in the proximity of hazardous properties (Step 2 in Figure 1), the hazards are categorized into 10 basic groups: mechanical, electric hazards, thermal hazards, noise and vibration hazards, radiation hazards, material and substances hazards, ergonomic hazards, hazards connected with the environment in which the machinery will be used, or a combination of these hazards. The risk matrix [38; 39] enables the estimation of the probability level of an analyzed hazardous situation, e.g., touching the cutting part when cutting materials and the severity of harm, such as cutting the hand or finger off, in a simple and usually qualitative way. It does this by assigning values to the probability and consequence levels, i.e., a framework for risk level estimation related to the respective hazardous property, e.g., a mechanical hazard that may arise during a performed activity (hazardous situation) when touching the cutting part of machinery (hazardous event), as shown in Table 1.