home › Acquisition of apartments › Methods for analyzing the causes of traumatism. Industrial injury. Logic symbol notation

Methods for analyzing the causes of traumatism. Industrial injury. Logic symbol notation

The most important stage in the investigation of accidents, occupational diseases, accidents, it is to find the main causes that led to negative consequences, as well as to determine the measures of responsibility of the perpetrators.
The purpose of the analysis of negative consequences is to develop preventive measures to prevent accidents and injuries.
The main methods of analysis include: probabilistic-statistical and deterministic. Probabilistic-statistical methods of analysis, in turn, are divided into: statistical, group, topographic, etc.
Statistical Method based on analysis statistical reporting about injuries and other negative events on the basis of reporting on the form H-1, NT, H-5, P-5 (accidents that resulted in disability for 1 day or more are taken into account).
When conducting the analysis, various indicators (criteria) and methods are used. The choice of methods and indicators (criteria) for evaluation depends on the adopted goals and objectives. The main goals and objectives include the analysis of accidents, injuries, occupational diseases, emergencies in various industries; analysis of the state of law and order; analysis of the effectiveness of preventive measures to prevent negative phenomena; analysis of the level of labor protection, etc.
A brief enumeration of the main goals and objectives indicates that some methods and indicators can be applied both within one industry and in a number of sectors of the country's economy. One of the most widely used both within the same industry and in a number of sectors of the country's economy are the average values of the analyzed factors - the arithmetic mean: geometric mean, harmonic mean, root mean square. For example, the average value in criminology can characterize the state of the crime rate; in medicine - average incidence; in the field of labor protection - the average value of injuries; in transport - average accident rate, etc.
Another relative intersectoral indicator can be the coefficient
, where A is the number of negative events (criminal situations, crimes, injuries, occupational diseases, etc.) for the reporting period; N is the number of employees or population for the reporting period; M is the conversion factor per 1000; 10,000; 1,000,000, etc. people.
In criminology, the coefficient K is considered the coefficient of crime. In the reports of the Ministry of Internal Affairs, the prosecutor's office, and law enforcement agencies, it is used to compare crime in different states, regions, and different time periods.
The severity of negative events is estimated by the coefficient of severity of accidents K T, and the coefficient of fatal ( lethal outcome) K C,
The state of injury is assessed overall coefficient injuries
Other indicators are also used: disability rate, indicators of the frequency and severity of diseases.
Disability rate: ;
Disease frequency indicator: ;
Disease severity index: ;
Safety indicator: ;
T - the number of days of disability in case of injury;
C is the number of deaths;
Z - the number of days of incapacity for work due to diseases;
About b - the number of safe operations;
О о - the total number of operations.

This method analysis allows you to get comparative evaluation on the state of labor protection at the enterprise, site.
Group method of analysis consists in separating the injured according to certain groups: profession, gender, work experience, age, qualification, etc. This allows you to identify the most vulnerable groups of people to injury or disease.
Topographic method is to study the causes of injuries by drawing on the plan of the workshop, area, landfill, enterprise, accident site. Recurrence of accidents in this place indicates a persistent safety violation.
If it is impossible to identify the causes of an accident, they often resort to deterministic (additional) methods of analysis: monographic, network modeling, questionnaires, surveys, expert assessments etc.
Monographic method based on the analysis of individual hazardous and harmful production factors.
The essence of the network modeling method dangerous production situation lies in the fact that after familiarization with the materials, a logical connection is established between all the phenomena that preceded the moment of injury (network relationship).
Example. An employee, a molder at a concrete products polygon, was given the task of assembling the formwork and installing reinforcement in it inside one of the curing chambers.
The crane serving the landfill was not working, and the worker himself carried the reinforcing meshes (the mass of one mesh is 15 kg) and walked with them on the covers of the chambers, which is prohibited job description on safety. While moving with the net, a worker fell into one of the cells and was seriously injured.
In the act of investigation in the column "Causes" it is written: "The cause of the accident was the fall of the victim into the steaming chamber with a depth of 2.6 m." In the column “List of measures to establish the causes” it is written: “Conduct an extraordinary briefing. Analyze the accident general meeting shops."
Has the cause been correctly identified and are the recommended measures sufficient?
Let's establish the logical connection of the reasons that led to the accident. The worker fell because he violated the instructions, and he violated the instructions because the crane did not work. As it turned out, the overhead crane did not work due to a sharp drop in temperature and a thick layer of frost on the crane trolls. A worker stepped into an open hatch due to poor visibility due to intense steam generation due to
malfunctions of valves on steam pipelines and a large temperature difference between the outside air and the steam-air mixture inside the steaming chamber.
Thus, the primary cause was a decrease in temperature, which gave impetus to the development of the entire chain of events up to the accident. The crane has stopped before because of frost on the trolley, but this violation of production technology was not controlled for various reasons. It was further established that the worker walked on the covers of the cells because the aisles were cluttered with finished products.
The master explained this violation of technological discipline by a violation of the schedule for the export of finished products. This method of investigation makes it possible to establish that the stopping of the crane and the deterioration of visibility in the work area are the main causes of the accident. Absence technical control and cluttering the area with finished products in this example are concomitant secondary causes.
To prevent such cases, it is necessary to: 1) replace the trolleys with a supply hose cable; 2) transfer the steaming chambers to automatic mode of operation; 3) strengthen control over compliance with the export finished products from the workshop.
Survey and questioning are made through a survey of eyewitnesses and allow you to identify the logical connection between the manifestation of negative consequences.
Method of expert assessments is to involve experts in the field (chemistry, physics, technology, medicine, etc.) in the investigation of the causes, which allows us to confirm the possibility of negative manifestations. When analyzing injuries, first of all, it is necessary to examine the place where the accident occurred, interview the victims, eyewitnesses, get acquainted with necessary documents, magazines.
Wherein Special attention should be given to parts of machines, mechanisms, tools, devices and objects that directly caused injury. This makes it possible to develop the right engineering solutions to eliminate such injuries, for which there are analysis methods.
When analyzing industrial injuries, one has to deal with various indicators due to the influence of a number of factors, conditions, and causes. In this case, it applies elimination method (a logical method, or a method of exceptions), with the help of which the influence of certain factors is excluded and one of them is singled out.
The causes of injuries and occupational diseases can be divided into the following four groups: technical (including technological), organizational, sanitary and hygienic and psychophysiological.
The technical reasons are cases associated with the presence of hazardous and harmful production factors in technological processes, unsatisfactory condition of safety devices, lack of funds personal protection; use of faulty equipment, tools, fixtures, etc.
For organizational reasons include: unsatisfactory organization of labor in the workplace; unsatisfactory organization of safety control; untimely and irregular supply of workers with personal protective equipment; poor-quality training of employees; non-compliance with instructions for the safe implementation of technological processes and use production equipment; unsatisfactory professional selection, etc.
For reasons of sanitary and hygienic nature include: non-compliance with the requirements of meteorological conditions in industrial premises(temperature, radiant and thermal energy, relative humidity, air velocity, barometric pressure); production noise, vibration; air pollution by harmful industrial gases,
vapours, dust; insufficient illumination of workplaces; unsatisfactory protection of workplaces from electromagnetic radiation, voltage of electric and magnetic fields, increased level of ionizing radiation, insufficient (in accordance with the requirements of sanitary standards) area of the workplace and the volume of the room per worker; non-compliance with personal hygiene requirements, etc.
For psychophysical reasons a deviation in the state of health can be attributed, including as a result of unsatisfactory professional selection (impaired vision, hearing, allergies, etc.)
Knowing the causes of injuries and occupational diseases makes it possible to eliminate dangerous and harmful production factors or develop preventive measures to improve labor safety.
Accounting and analysis of injuries allow not only to identify the causes of injuries, but most importantly, to correctly develop and implement labor protection measures, to reduce injuries (Fig. 1.5.1).
One of the main tasks of accounting for injuries is a detailed study of the causes of injuries, their thorough and complete registration. This makes it possible to reliably assess the working conditions and organization of the workplace at the time of injury. For each accident, occupational disease, accident and other negative consequences at the enterprise, their consequences (losses) are determined:

P \u003d P b + P M + P O + P Z + P and + P pr (1.5.1)

Pb, Pm, P O, PZ, P i, P pr - disability losses, damage to materials, equipment, buildings and structures, tools, non-manufactured products.
The effectiveness of labor protection measures is evaluated according to the following dependence:

E \u003d (O P1 - O P2) - Z O.T. (1.5.2)

O P1 and O P2 - losses from injuries, occupational diseases, accidents before and after the events for a certain period;
Z OT - the cost of labor protection measures for the period under review.
The annual savings in the cost of production from improving working conditions is determined by the dependence:

E C \u003d E T + E Z + E P.Z. + E T.K. (1.5.3)

E T, E Z, E P.Z, E T.K. – annual savings from reducing injuries, diseases, occupational diseases, staff turnover.

Methods for predicting negative events

Forecast methods allow not only to assess labor protection issues, but also to predict the dynamics of the development of injuries, crime, accidents, occupational diseases and other events for the future period of time, to develop preventive measures, strategic comprehensive plans and thus influence the development of events in the future.
One of the forecasting methods can be correlation dependencies (regression models) that describe changes in negative events from basic indicators, for example, a model of the dynamics of changes in the level of injuries, occupational diseases, accidents depending on the level of labor productivity, labor productivity opportunities; changes in the level of crime by region - depending on the population, etc.
The criterion for safe work on the site, in the team, can be taken as the probability P, which is determined by the formula:

(1.5.4)

where T 3 - a given period of time for which the value is determined; N is the number of brigades or sections; n is the number of recorded cases of injuries (diseases) in N brigades during time T.

The results are considered reliable, that is, they provide the main condition (safety of work for the period T 3) if: . If<0,95, то полной уверенности в безопасной работе за период Т 3 быть не может.

Example. For three years of work (T=12 quarters) in four brigades of bricklayers (N=4) there were 12 accidents (n=12). It is necessary to find out whether industrial accidents can occur in these teams during the first half of the year (T 3 \u003d 2 quarters) of the next year.

The result obtained suggests that there can be no absolute confidence in the safe work of masons' teams over the next six months with this organization of labor. For safe work, it is necessary to rethink the organization of the work of masons' teams.
If a random variable has a Poisson distribution, then, taking into account time, we can talk about the simplest flow of events (injuries, fires, crimes, etc.). Probability of safe operation for a period of time t at K events

K=0, 1, 2…,

where is the intensity of the flow, that is, the number of events occurring per unit of time.
P is the probability that at least one injury can occur in the same period:

(can be interpreted as a risk of injury).

Similar principles form the basis of several models of the labor safety criterion.
Essence probabilistic method is as follows.
First, when analyzing injuries at a particular enterprise, it is established that the number of injuries and occupational diseases has a Poisson distribution.
Secondly, according to the formula P, the probability of at least one injury or occupational disease, crime is determined.
Thirdly, the number of injuries and diseases in the future is estimated over time at enterprises, sites, in teams with established technology.

П = Р∙t 1 (1.5.5)

Fourthly, the total economic damage is determined, which consists of the economic damage on sick leave and the damage from failure to fulfill the plan in the future:

(1.5.6)

where M is the conversion factor for 100, 1000, etc. workers; D is the number of employees at the enterprise;
- total costs for n sick leaves for a certain period (in UAH);
- total damage due to non-fulfillment of the plan by workers during the injury period
Fifthly, the costs of measures to prevent such accidents are determined.

An analysis of industrial injuries allows you to discover the causes and determine the patterns of their occurrence. Based on this information, measures are developed to prevent industrial injuries. For the analysis of industrial injuries, the following basic methods are used: statistical, topographic, monographic, economic, questionnaire method, method of expert assessments

Statistical Method is based on the study of injuries according to documents: reports, acts, registration logs. This allows you to group the cases of injuries according to certain criteria: by the professions of the victims, by workplaces, workshops, length of service, age, causes of injury, equipment that caused the injury.

To assess the level of injury, the coefficients of its frequency and severity are calculated:

K h \u003d A * 1000 / T

where K h - coefficient of frequency of injuries;

A - the number of injuries at the enterprise for the reporting period;

T - the average number of employees at the enterprise for the same reporting period,

K t - injury severity coefficient,

D - the number of days of disability for the victims (in working days).

The injury frequency rate, in fact, shows how many cases of injury for the corresponding period (six months, a year) occur per 1000 average employees at the enterprise, and the injury severity rate shows how many days of disability there are on average per one case of injury for the corresponding period.

The coefficients K h and K t make it possible to study the dynamics of injuries at the enterprise (for 4-5 years), to compare it with other enterprises.

Monographic method consists in a detailed examination of the entire complex of working conditions, the technological process, equipment, workplace, working methods, sanitary and hygienic conditions, collective and individual protection equipment. In other words, this method consists in the analysis of hazardous and harmful production factors inherent only in one or another production site, equipment, technological process. According to this method, all the circumstances of the accident are considered in depth, if necessary, then appropriate studies and tests are performed. The shop, section, technological process, main and auxiliary equipment, labor practices, personal protective equipment, conditions production environment, meteorological conditions in the room, illumination, gas contamination, dustiness, noise, vibration, radiation, causes of accidents that occurred earlier at this workplace. Thus, the accident is studied comprehensively.

Topographic method is based on the fact that on the plan of the workshop (enterprise) they mark the places where accidents occurred. This allows you to visually highlight places with increased danger, which require a thorough examination and preventive measures. The repetition of accidents in certain places indicates the unsatisfactory state of labor protection at these facilities. Special attention is paid to these places, the causes of injuries are studied. By additional examination of the mentioned places, the causes that caused accidents are identified, current and prospective accident prevention measures are formed for each individual object.

economic method consists in the study and analysis of losses caused by industrial injuries.

Questionnaire method. Questionnaires for workers are being developed. On the basis of personal data (answers to questions), preventive measures are developed to prevent accidents.

Method of expert assessments is based on expert conclusions (assessments) of working conditions, on the identification of compliance technological equipment, devices, tools, technological processes to the requirements of standards and ergonomic requirements related to machines, mechanisms, equipment, tools, control panels.

Under the influence of harmful factors in the workplace, workers may experience acute occupational or chronic poisoning and diseases.

However, the impact of production factors is not limited to their role as the cause of occupational diseases. It has long been observed that people working with toxic substances are more likely to suffer from common diseases (flu, digestive disorders, pneumonia, and the like), that these diseases are more difficult for them, and the recovery process is slower. Therefore, in addition to indicators of the frequency and severity of occupational morbidity (determined similarly K h and K t), it is also important to determine indicators of the level of general morbidity. For this purpose, the indicator of the frequency of cases of diseases and the indicator of days of incapacity for work, which fall on 100 employees, are calculated.

Statistical method for analyzing the causes of industrial injuries Today, the statistical method for analyzing the causes of industrial injuries is perhaps the main method that allows developing a policy of action and outlining specific measures to prevent this sad and undesirable phenomenon. For analysis, an array of data is collected for all studied indicators. With the help of statistical analysis, it is possible to detect patterns inherent in these indicators, to study the features of the occurrence of accidents in ...

Share work on social networks

If this work does not suit you, there is a list of similar works at the bottom of the page. You can also use the search button

50. Statistical method for analyzing the causes of industrial injuries

The statistical method for analyzing the causes of industrial injuries is used today, perhaps, main method,allowing to develop a policy of action and outline specific measures to prevent this sad and undesirable phenomenon.

The analysis is subjected to a predetermined limited number of certain indicators of an accident.For analysis, an array of data is collected for all studied indicators.

Statistical analysis can detect patterns,characteristic of these indicators,to study the features of the occurrence of accidents in certain professions,in separate production areas,for certain categories of workers.The strength of the statistical method for analyzing the causes of industrial injuries ability to predict.

Injuries are considered as a function of various variables.Identification of the most significant of these variables and the nature of their impact on injuries that's the main goal of this approach.When using this method of analysis, the randomness of an individual event recedes into the background,clearing the way for REGULARITY.To paraphrase a famous Russian proverb, you can say that the statistical method allows you to see the FOREST instead of a lot of trees! It cannot be used to develop any specific recommendations for the prevention of individual accidents. it aims to identify common ways to deal with certain types of injuries.

Statistical analysis is difficult to prevent a specific accident,but relatively easy their whole class. This is his strength.

The use of the statistical method involves the selection from all available information of relatively homogeneous“groups” data for individual features:injury time,the place of injury, gender and age qualifications and specialties of the victims,the type of work performed in case of injury,the type of cause of the accident, etc.The results of the analysis for these and other most significant signs of injury allow us to develop appropriate preventive measures.

Note that good results are obtained by combining the statistical method of analysis with the method of economic loss analysis,caused by accidents. This allows ( especially for the owner) evaluate the socio-economic efficiency of measures taken by the employer to prevent industrial injuries.

Other related works that may interest you.vshm>
569.		Calculation of indicators (coefficients) characterizing the state of industrial injuries	168.57KB
	Calculation of indicators of coefficients characterizing the state of industrial injuries national economy in general, as well as to compare the state of injury in these structural divisions relative indicators of the frequency of severity of accidents and disability are used. The indicators are calculated on the basis of the data of the report on victims of accidents. The indicator of the frequency of accidents...
9227.		Methods of quality control, analysis of defects and their causes	37.22KB
	If a large number of standard sizes of products are manufactured in the workshop, then the standard sizes of parts are laid out horizontally and types of defects often turn out that one standard size accounts for a very large part of all damage from marriage. Let's take and measure 50 parts in a row, as a result we can get the following values of the table. is an unordered sequence of part diameter values from which it is difficult to draw any conclusions.
10054.		Conducting a comprehensive analysis of the causes and consequences of the global financial crisis	94.07KB
	The first chapter describes theoretical basis various points view of what is the global financial crisis and the causes of its occurrence and its essence. This is because financial markets inherently non-equilibrium and demonstrate increased sensitivity to dynamics environment reflexively affecting her. The financial crisis has affected almost all countries of the world except for those that are already in the financial economic crisis.
10649.		Index method of analysis	121.13KB
	individual indexes. General aggregate indexes. Average converted indexes. Indices of variable and constant composition indices of structural shifts.
19802.		The method of conducting a strategic analysis - SWOT analysis	19.78KB
	Estimate internal environment firms - its strengths and weaknesses as well as external and internal opportunities and threats are commonly referred to as SWOT - analysis. The concept of SWOT - analysis The most important stage in the development effective strategy firm is strategic analysis which should give a real assessment of its own resources and capabilities in relation to the state and needs external environment in which the company operates. However, in a dynamically changing environment, even for relatively small ...
15930.		Functional cost analysis method (FSA). Improvement of labor activity on the basis of FSA	70.2KB
	The ratio of the functions of the governing bodies to the managed object provides information on how necessary this body is. Correspondence of the functions of the control system with the functions production system the necessary conditions effective building organization management systems, since the management system does not exist by itself, but to ensure the effective functioning of the production system. Analytical stage Formulation analysis and classification of PMO functions, their decomposition, analysis of functional relationships between OUT and gene. The most important...
12483.		The study of childhood trauma and ways to prevent it	52.58KB
	Children are sent to schools, kindergartens, various centers additional education parents hope that their children will return safe and sound. 38] Parents often blame schools, kindergartens, additional training centers and other educational institutions for the fact that conditions excluding injuries are not created, teachers, in turn, blame parents for improper upbringing of children. Because of a large number children at recess and the unbridled children's energy accumulated during the lesson of moving from class to class, these factors ...
17774.		STATISTICAL ANALYSIS OF THE COST OF MILK PRODUCTION	90.41KB
	The production of agricultural products, including milk, is the main goal of agricultural enterprises. But in addition to data on the size of manufactured products, it is very important to know what this product cost, that is, its cost.
1183.		Statistical analysis of the state of fixed assets	622.7KB
	Economic entity fixed assets. The concept and essence of fixed assets. Types of fixed assets and tasks of statistical study. Statistical analysis of the state of fixed assets.
12233.		Statistical analysis of the Hellenic Republic as a tourist destination	284.65KB
	Greece has a well-developed tourism sector and the income generated is a significant part of the country's GDP. All these factors allow us to conclude that the economic, social, political and tourist situation of modern Greece is ambiguous. In this research work an attempt is made to analyze the current state of Greece as a tourist destination on the basis of official statistics.

What is the topographic method?

The topographic method for analyzing the causes of industrial injuries is that the site plan marks the places where accidents occurred. If at certain workplaces they are periodically repeated, then this indicates an imperfect organization of the working regime and the dysfunction of these places.

The concentration of accidents at such workplaces gives the employer reason to take the necessary measures to find out the true causes of accidents in order to develop appropriate measures. The advantage of the topographic method of analysis is its simplicity, convenience and clarity.

How is the monographic method of traumatism analysis carried out?

This method provides for a detailed survey of objects that are in operation or are just being designed or built, in order to identify obvious or potential hazards. It is used to determine the causes of accidents that occur in difficult working conditions, to clearly define measures.

The monographic method reveals not only the causes of accidents that occurred earlier, but also potential hazards and harmful factors that can lead to disruption of the normal work process and inadequate response of workers.

This method studies in detail the production circumstances, working conditions, features of the technological process, the condition of machines, equipment, etc. To determine the causes of accidents, victims are grouped by profession, gender, age and work experience, and injuries are divided by type of work and the nature of the actions of the traumatizing factors, the time of their occurrence and the nature of the damage.

The results of the monographic method of analysis in homogeneous industries are used in the reconstruction or design of industries or technological processes of the same type.

How is the statistical method of injury analysis carried out?

The statistical method for analyzing industrial injuries is used to determine quantitative indicators that characterize the overall level of injuries. The basis of the statistical method is the study of accidents according to acts in the form H-1. For this, relative values are used - indicators (coefficients) of frequency, severity and general disability losses.

The frequency indicator (# ") characterizes the number of accidents per 1000 employees for a certain period of time and is determined by the formula:

where T - the total number of injuries for the reporting period (six months, a year), is established according to closed sick leave;

P - the average number of employees for the same period.

The injury severity index (Ia) characterizes the overall severity of injuries during the analyzed period. This value shows how many days of disability per injury, and is determined by the formula:

where D is the total number of days of temporary disability for all accidents recorded during the reporting period.

The overall level of industrial injuries (I.) is calculated by the formula:

This indicator takes into account the number of days of disability per 1000 employees during the reporting period.

Comparison of the calculated indicators makes it possible to identify the most unfavourable conditions and take appropriate measures to prevent workplace injuries and create healthy and safe working conditions.

Material damage from accidents are determined in the reporting?

In static reporting indicate:

sick leave payments;

the cost of damaged equipment, tools and materials;

the cost of destroyed buildings, structures and other costs.

What are the material losses from industrial injuries?

The main elements that make up the material damage of industrial injuries for the reporting period include:

payment to victims on disability certificates P1

pension assigned to the victim in connection with the injury P2

pension granted to close relatives of the victim in connection with the loss of a breadwinner (P3);

help with temporary transfer employee to another job due to injury (P4)

compensation for damage to an employee in case of partial loss of working capacity P5

costs of the employer for the professional training of the employee who is hired instead of the one who left due to injury (B6)

other losses (B7).

By summing up certain component indicators, you can calculate the total material costs (in rubles):

Statistics show that the highest percentage material costs from industrial injuries are payments for sick leaves of incapacity for work (more than 50%).

Approximate material damage of industrial injuries can be determined by the formula:

where FDI - total material losses;

Days - the total number of days of disability for the reporting period;

Zsr - average wage victims;

1.5 - coefficient taking into account material costs.

The obtained indicators are used to determine economic efficiency measures to prevent industrial injuries.

1. ANALYSIS OF INDUSTRIAL INJURIES

1.1. Causes of industrial injuries

and methods of its analysis

To improve working conditions in production, the task is always set to establish the causes and patterns of occurrence of accidents and occupational diseases. This is preceded by a deviation production process from normal running.

Causes of industrial injuries

Currently, the following causes of industrial injuries are distinguished in the analysis.

1. Organizational - lack of or unsatisfactory briefing and training in safe work practices; lack of a project for the production of works, management and supervision of work; unsatisfactory mode of work and rest; improper organization of the workplace, movement of pedestrians and vehicles; absence, malfunction or non-compliance with the working conditions of overalls, personal protective equipment, etc.

2. Technical reasons are divided into three types:

a) design - non-compliance of building structures, process equipment, transport and energy devices with safety requirements; imperfection of the design of mounting equipment, manual and portable mechanized tools; absence or imperfection of protective fuses and other technical means security;

b) technological - the wrong choice of equipment, tooling lifting mechanisms and means of mechanization; violation of the technological process;

c) unsatisfactory Maintenance– lack of scheduled preventive inspections, technical maintenance and repair of equipment, tooling and Vehicle; malfunction of hand and portable power tools.

3. Causes of the unsatisfactory state of the production environment - unfavorable meteorological conditions; unsatisfactory illumination; increased noise and vibration levels; increased concentration of harmful substances in the air of the working area; the presence of harmful radiation, etc.

4. Psychophysiological - discrepancy between the anatomorphological and psychological characteristics of the human body and working conditions; unsatisfactory psychological climate in a collective ; alcohol intoxication, etc.

Methods for the analysis of industrial injuries

In the analysis of industrial injuries in order to establish and eliminate the causes that cause them, various methods are used:

– topographic: consists in studying the causes of accidents at the place of their occurrence. All accidents are systematically applied with symbols on the work plans, as a result of which the places and production sites where the injury occurred;

– statistical: is based on the study of the causes of injuries according to documents registering the facts of accidents (acts in the form H-1) for a certain period of time. This method makes it possible to obtain a comparative dynamics of injuries for individual production facilities. With in-depth statistical analysis, it is carried out by type of work, where information about the victims (profession, work experience, gender, age, etc.) and data on the time of the incident (year, month, day of the week, shift, hour of the working day, etc.) . P.);

– group: based on the study of repetitive accidents regardless of the severity of the injury. The available material of the investigation is divided into groups in order to identify accidents that are the same in terms of circumstances, occurred under the same conditions, as well as recurring in the nature of damage. This allows you to determine the most traumatic professions and types of work;

– monographic: includes a detailed study of the entire complex working conditions in which the accident occurred: labor and technological processes, workplace, main and auxiliary equipment, individual funds protection, general conditions of the working environment, etc. .

Quantification of occupational injuries

A number of indicators are used to assess the level of industrial injuries.

Injury frequency rate, which is the number of accidents per 1,000 workers in a given period

where N- the number of accidents that occurred in the organization during the period under review;

R- the average composition of employees in the organization for the period under review.

The injury severity coefficient represents the average duration of temporary disability per one accident that occurred at work

where is the total number of days of disability due to injuries for the period under review.

The fatal accident frequency rate is the number of fatal accidents per 1000 employees and is taken equal to

, (1.3)

where is the number of fatal accidents for the period under review.

Example: Calculate the frequency coefficient and the severity coefficient of injuries for a construction organization of 800 people, if it is known that over the five years of its operation there have been 6 accidents with loss of temporary ability to work with a total duration of 72 days.

Solution: To determine the coefficients of frequency and severity of injuries in the organization, we use formulas (1.1) and (1.2):

;

1.2. Risk analysis methods

Risk is a quantitative assessment of danger, which is expressed as the ratio of the number of certain adverse consequences to their possible number for the period under review.

Applied to production activities the concept of the risk of industrial injuries is used as a quantitative indicator of safety. It determines the actual measure of the probability of damage to the health or death of a worker due to the impact of hazardous production factors on him in the performance of his duties. job duties. The risk of industrial injuries is largely determined by the qualifications and training of workers to act in a dangerous situation and their security. In the analysis, the risk value is not determined for each employee. This value can be determined for a group of people characterized by the same time spent in hazardous conditions, for example, for a team of finishers, etc.

Risk value R can be defined as the expected value of damage n, caused over a period of time Dt, referred to a group of people numbering P human:

The concept of risk always includes two elements: the frequency with which a hazardous event occurs and the consequences of the hazardous event.

Risk assessment includes frequency analysis, consequence analysis, and a combination of the two. Therefore, it is advisable to consider risk analysis as part of systems approach to the adoption of decisions and practical measures in solving the problems of preventing or reducing the danger to human life, diseases or injuries, damage to property and the environment.

Planning and organization of work;

Hazard identification;

When planning and organizing work, the reasons and problems that caused the need to conduct a risk analysis are described.

When identifying hazards, the main task is to identify (based on information about the safety of a given object, the results of examinations and the experience of such systems) and a clear description of all the hazards inherent in the system.

In principle, the risk analysis process can end at the stage of hazard identification. Only if necessary, after identifying the hazards, you can proceed to the other steps described above.

1.3. Hazard identification methods

Hazards can be identified using the following main methods:

- "fault tree";

- "event tree";

Equivalent.

The methods can be applied individually or in addition to each other. Qualitative methods may include quantitative criteria risk. A complete quantitative risk analysis may include all of these methods.

Methods "what happens if ...?" and checklist belong to the group of qualitative methods of hazard assessment. The result of these methods is a list of questions and answers about the compliance of the object with safety requirements and developed recommendations for ensuring safety.

An analysis of the causes of industrial accidents shows that their occurrence is usually characterized by a combination of random local events (equipment failure, human error, etc.). To identify cause-and-effect relationships between these events, the logical-graphical methods "fault tree" and "event tree" are used. Fault tree analysis reveals combinations of equipment failures, human errors, leading to an accident at work. The method is used to analyze the occurrence of dangerous situations and calculate its probability (based on knowledge of the probabilities initiating events).

To analyze the development of a dangerous situation, the "event tree" method is used. In this method, the frequency of each accident scenario is calculated by multiplying the frequency of the main event by the probability of the end event.

Tree analysis methods are the most time-consuming and are used to analyze projects or modernize complex technical systems and industries, and require highly qualified performers. Therefore, let us consider in more detail the application of the "fault tree" method, which is used in production to determine the causes of equipment failures.

The method consists in building and analyzing a model that is a logical-probabilistic model of cause-and-effect relationships of product failures with failures of its elements and other events. The basic principle of building a "fault tree" is to consistently ask questions and give answers for what reasons a product may fail. Logic symbols and event symbols are used to visualize the causal relationship with the help of a “fault tree”. Logical symbols link events according to their causal relationships. Symbol designations are given in Table. 1.1, and the symbols of events in Table. 1.2.

Table 1.1

Logic symbol notation

logical	Name logical	Causal relationship
		output event happens if all input events happen at the same time
		output event occurs if any of the input events occur
	"BAN"	The presence of an input causes the appearance of an output when when the conditional event occurs
	priority "AND"	An output event occurs if all inputs events take place in order from left to right
	Exclusive "OR"	output event occurs if one (but not both) of the input events occurs
	"m" from "n"	output event happens if "m" of "n" inputs happens

Table 1.2

Event Symbol Designations

Event Symbol
	Source event provided sufficient input
	Event is not enough detailed
	Event injected logical element
	Conditional event used with logical sign "prohibition"
	An event that can happen or not happen
	Jump symbol

Schemes for the use of symbols of logical signs and symbols of events, depending on the initial events 1,2, ..., n in the diagrams of the "fault tree" are shown in fig. 1.1. and 1.2.

Rice. 1.2. Using the logical symbol "OR"

Example 1: Identify risk R death of a person in construction industry in our country for 1 year, if it is known that 600 people die every year, and the number of workers is 700,000 people.

Rice. 1.3. Fault tree for a metal cutting machine

Solution: To determine the risk of human death, we use the formula (1.4):

Example 2 Using the "fault tree" method, evaluate the probability of failure of the machine of the drilling and boring group. The main movements of the machine are: the main cutting movement, i.e., the rotation of the tool and the feed movement of the cutter.

Solution. Machine failure can occur due to a functional failure resulting from sudden failures of blocks, assemblies, parts of the machine, or due to a parametric failure, which will occur when the technological reliability is exhausted, as shown in Fig. 1.3.

A functional failure may occur if the following predictable causal chains of hazards are realized that will cause the machine to stop:

Motor failure;

Fuse failure;

Short circuit of the electrical wire to the body;

Pump failure;

Relief valve spring failure;

Throttle failure;

check valve failure;

Loss of tightness in the oil pipeline;

Failure of the limiter of the mobile gear wheels of the gearbox - stopping the machine;

Gear box failure;

Based on our reasoning, we will build a "fault tree" of a metal-cutting machine, as shown in Fig. 1.3.

On fig. 1.3 marked: 1 - failure of the electric motor; 2 - failure of the limit switch; 3 - short circuit of the cable to ground; 4 - fuse failure; 5 - short circuit to the body; 6 - pump failure; 7 - broken valve spring; 8 - throttle failure; 9 - check valve failure; 10 - safety valve failure; 11 - oil pipeline leaks; 12 - main engine clutch failure; 13 - failure of the clutch of the first shaft of the gearbox; 14 - failure of the gear wheels of the gearbox; 15 - failure of the limiter of the mobile gear wheels of the gearbox; 16 - failure of the gears of the feed box; 17 - failure of the clutch of the gears of the feed box.