With the increase of industrial activities and the expansion of technology, industrial environments have increased. In traditional systems, after accidents and irreparable damage, the causes of accidents were investigated, and the defects of a system or process were determined. But today, due to the existence of different methods of hazard identification and risk assessment, before accidents can be points Identified accident-prone and critical areas and take action to prevent and control accidents. Join us to learn how to do it and the steps of risk assessment, and the methods to do it thoroughly.

make your business continuty plan risk assessmentWhat is a risk assessment?

Risk identification and risk assessment are organized and systematic methods for ranking and prioritizing risks and making decisions to reduce risk to an acceptable level.

All production and industrial operations and activities require requirements, the failure of each of which can lead to unintended consequences in the form of injuries to domestic and foreign personnel and customers, damage to production processes and products, services provided, environmental damage, damage to credibility. And the reputation of the organization and other important assets.

At present, due to the growth of the industry, technology, and the complexity of risks and to prevent and reduce the human and financial consequences of accidents, risk management, and control, as well as teaching the concepts of risk identification and risk assessment, knowledge of methods, techniques and their use in Establishing a safety system for production and industrial units is essential.

Place and purpose of risk identification and risk assessment

The text of safety management system standards such as OHSAS 18001 and MS – HSE emphasizes risk identification and risk assessment and is mentioned as the heart of the system.

According to these requirements, the organization must continuously create, implement, and maintain an implementation method to identify risks, assess risk, and determine the necessary controls.

The implementation method of risk identification and risk assessment should consider the following:

1. Routine and non-routine activities

2. The activities of all people who have access to the workplace, including contractors and visitors

3. Human behavior and capabilities and other factors

4. Identified hazards that originate outside the workplace and can have a detrimental effect on individuals’ health and safety under the control of the organization.

5. Risks created in the vicinity of the workplace by work-related activities under the control of the organization (environmental aspects)

6. Infrastructure, equipment, and materials in the workplace (provided by the organization or others)

7. Proposed changes or changes in the organization, its activities, and materials

8. Modification and change in occupational safety and health management system, including temporary changes and its effect on operations, processes, and activities

9. Any applicable legal requirements about risk assessment and the application of necessary controls

10. Design of workspace, processes, installations, machinery and equipment, operational methods, and work organization, including adaptation to human capabilities

11. The organization’s methodology for identifying risk and assessing risk should be defined according to the scope of application, nature, and timing of the organization to ensure that it is an action rather than a response method.

12. Provide appropriate identification, prioritization, and documentation of risks and implementation of control measures.

13. To manage change, the organization must address occupational safety and health hazards and the risks involved

Significantly changes in the organization, occupational safety, and health management system or its activities, before starting Identify such changes.

14. The organization should ensure that the results of these evaluations are taken into account when determining controls.

15. The organization should document and keep up to date the results of hazard identification, risk assessment, and control measures.

Risk assessment applications

  • Review safety and operations for all large and expensive projects to ensure essential design considerations are satisfactory.
  • Identify and analyze hazards to develop and implement safety guidelines.
  • Review the dangers and risks in the executive procedures, operational sheet, and critical tasks to determine their appropriateness.
  • Safety review before starting work to ensure that the facilities and conditions for carrying out work operations are appropriate.

The right time to assess risk

  • The most appropriate time to start a risk assessment is in the design phase.
  • Despite this assessment, the ongoing threat is an essential priority throughout any system’s life cycle.
  •  Risk assessment is a necessary prerequisite for making a change in the work environment, whether physical or operational, or organizational.

Risk definition

Risk is the probability that a hazard will cause injury and damage multiplied by the severity of that injury.

So the risk is the potential for danger to become a reality. Mathematically the bet multiplied by the probability of a Special adverse event (such as bodily injury, fire, etc.)is due to that event.

Risk = P × C

Probability of recurrence: The occurrence of an adverse event usually with its chance in a certain period or its frequency (The number of events per unit time) is measured and expressed.

C: Consequences of the event

Risk Analysis

Risk analysis is a quantitative risk assessment based on engineering assessments and mathematical techniques by estimating the probability and the outcome of the accident and their combination. In other words, the systematic use of available information to determine repetition and intensity are the consequences of specific events.

Risk Evaluation

Evaluation is the process that uses the results of a risk analysis (i.e., estimated risks) to make decisions by ranking or comparing them with target values (performance objectives or legal requirements). Risk assessment shows whether the chances are acceptable or not.

Risk Elimination

Usually, the first option is to eliminate the risk so as not to cause harm. Unfortunately, risk elimination is always is not possible. In other words, not all risks can be eliminated.

Risk Modification

Some risks can be remedied by reducing the inherent risk. An example is isolating a compressor that makes a lot of noise. Another risk correction method is to apply control measures using rules, regulations, enforcement procedures, and laws. Comprehensive training, education, and supervision are valuable methods of risk management.

Risk Tolerance

Managers must decide whether the risk is tolerable. Sometimes we modify the chance to be less than fair, and periodically we can not change the risk to a modest level. Managers need to be aware of risk tolerance.

Risk Communication

It is the communication of risk results to decision-makers and the public. Risk perception strongly affects the type and level of acceptable risk. Public protests strongly influence decisions, so risk reporting should be considered a complementary part of risk management.

Risk transfer

Even by applying the organization’s best risk management measures, we find that we still face significant financial risk. Insurance is a way of transferring some risks. Another way to share risk is to use contracting. An example is the use of rental cars.

Risk Management

Planning, organizing, directing, and controlling the organization’s activities and assets so that the adverse effects on its performance and economy due to accidents are minimized. In short, any action to reduce risk is called risk management. Bets cannot be eliminated but can be reduced to an acceptable or tolerable level. Therefore, risk management aims to create a systematic and continuous framework for identifying, evaluating, stopping, controlling, preventing, reducing, and communicating risks. In the risk management process, decisions are made based on comparing the results of risk assessment with objective and technical, social, economic, and political judgments.

Risk management is used as a set of activities using resources to control and monitor the system under study and control risk and its effects. Risk management is used to reduce the potential risks associated with the risks related to the risks attributable to each aspect of a system’s power.

Risk assessment is a process of gathering information to make scientific and transparent decisions to determine the level of risk associated with risk. Risk assessment is a structured and systematic method for identifying risks and risk estimation for ranking decisions to reduce risk to an acceptable level.

Generally, in the workplace, many risks are identified that due to limited resources and time, more critical risks should be controlled first and then addressed other risks. Therefore, the risk assessment process should be used. In other words, risk assessment helps the organization to identify its priority in terms of safety correctly and to be careful in allocating resources to have the most significant impact on the safety management system.

Explain the risk methodology

Calculating and measuring the amount of risk:

Risk is always expressed numerically, usually obtained by multiplying the probability of occurrence by the outcome or severity of the event. The risk number does not have a specific unit and, therefore, will not have meaning only. For example, if it is said that the risk of doing a particular job or activity is 200, it does not make any sense. However, if the risk of doing two similar tasks or doing the same thing in two different ways or the threat of doing other tasks is determined, it is possible to compare the risk numbers, and thus the importance is specified.

Risk assessment criteria

In this method, risk assessment is based on the following four factors:

  1. Contact (Exposure)
  2. Probability (Likelihood)
  3. Severity
  4. Possibility of Detection


Indicates the duration of the call or activity or event under review.

Probability (Likelihood/Frequency)

Indicates the possibility of a hazard joining in a certain period.


Indicates the extent of the damage and loss that would occur if the hazard occurred.

Intensity classifications include:

1. Catastrophic, critical, severe, serious (US Transportation Safety Board Classification)

2. Catastrophic, broad, painful, small (US Space Agency classification )

3. 1st floor, 2nd floor, 3rd floor, 4th floor (National Security Council of the US)

Risk Score (Initial risk rating)

Is the product of contact and probability and consequence (intensity). Which is displayed in lower case and is done for initial and preliminary evaluation.

that’s mean:

r.s = E * L * C

Detection probability rate

• The likelihood of discovering is an assessment of the ability to identify a cause/mechanism of a hazard occurrence. In other words, the probability of discovery; The ability to detect danger before it occurs.

• After measuring the risk rating (E * L * C), multiply the result by the probability of discovery and

We get the real level of risk of the subject.

Activity risk level and schedule


Work should not be started until the risk has been reduced, even if using all resources; If risk reduction is not possible, work activity must be stopped.


Work should not begin until the risk has been reduced. Significant resources are needed to reduce the risk.

Be allocated.

Acceptable – need to be revised

Efforts should be made to reduce the risk, but the costs incurred should be carefully considered and limited.

Measurement of risk reduction can be done in specific periods.

When the moderate risk is associated with severe traumatic outcomes, the likelihood of that risk should be carefully assessed. The need to increase and improve control measures should be considered.


No more control is needed. The cost-effective solution must be considered and also ensured

Controls are in place.

Risk assessment matrix

Partial 4

Border 3

Critical 2

Catastrophic 1

Danger intensity

Probability of danger

4A 3A 2A 1A

Frequent A 4B 3B 2B 1B

Probable B 4C 3C 2C 1C

Casual C 4D 3D 2D 1D

Very low or unlikely D 4E 3E 2E 1E

Unlikely (but possible)

Steps of risk assessment and management

Risk assessment steps

  •  Risk forecasting
  •  Risk identification
  •  Initial risk assessment
  •  Risk measurement
  •  Risk assessment
  •  Risk control

An appropriate and adequate risk assessment should:

  • Analyze the possible consequences of an event
  • Identify significant risks and assess the chances of an outcome
  • The basis of judgment is whether the product is tolerable or intolerable
  •  Provide information for decision making and prioritization
  • Determining potential harming factors and their effects
  • Evaluation of potentially damaging elements and their effects
  • Specifying the details of goals and performance criteria
  • Establishing set criteria
  • Take selective measures to reduce risk
  • Document potential harm factors and their impact and apply legal requirements
  • Determine risk reduction measures
  • Determining the relevant legal requirements
  • Among the objectives of the risk assessment process objectives are to reduce the severity and recurrence of the accident, minimize damage to property and machinery, provide safe and healthy working conditions, and prepare regulations.
  • Eliminate suffering, identify training needs, develop safety plans, prioritize and allocate
  • Resources, preparation of documentary evidence, reduction of financial losses due to cessation of production operations are among the benefits of risk assessment.

When to assess risk?

The most appropriate time to start a risk assessment is in the design phase.

Despite this assessment, the ongoing risk is an essential priority throughout the life cycle of any system.

Risk assessment is a necessary prerequisite for making a change in the work environment, whether physical or executive, or organizational.

Considerations for conducting a risk assessment

The following issues should be clarified before conducting any risk assessment:

1. Purpose and final use of risk assessment

2. Define the system being analyzed

3. Categorize the main concerns

4. Previous information sources used

5. Time constraints when presenting a risk assessment

6. People needed and available to support risk assessment at various stages

7. Methods used

Risk assessment requirements:

The following conditions are common to most methods and determine the quality of risk assessment results:

1. Existence of a qualified leader and coordinator

2. Forming a group (a large number of people lead to problems in achieving results)

3. Group members should be thoroughly familiar with the risk assessment method used.

4. Appropriate people who have different input from each other, such as people in the field of technical experts

5. Drawing the system, operating sheets, operating methods, and previous records

6. Knowing the existing structure or related technology

7. Document the results

8. Tracking system

Process risk management team

1. Safety and Health Engineering Representative

• Have good knowledge in the field of risk/risk analysis

• I had a strong background in all areas of production

• skills in team leadership and as a team leader

2. Representative of the engineering unit

• Have good knowledge of design practices and standards

• Having an excellent working knowledge of the design of the unit understudy

• Optimal engineering experiences during active years

3. Representative of the technology unit or R&D

– Having good knowledge in the process technology of the unit understudy

Desirable experiences during years of work in process technology

4. Impartial representative

– Production engineer from another unit, preferably from another factory with a similar process

– Optimal experience and expertise in operational and technological aspects

5. Representative of the operating or production unit

– Having a good and detailed knowledge of design and production

– Production experiences in the process

– Optimal production experiences during years of work

6. Maintenance representative

– Having good knowledge in identifying equipment and devices

Desirable experiences during years of work in process technology

– Knowing maintenance and design and production problems

7. Besides, according to the evaluation conditions, should be added to the team of these people:

1. Electrical Engineer

2. Process / Tool Control Engineer

3. Project Engineer

4. Mechanical Engineer

Steps to perform a risk analysis

1.The first step is to understand and define the physical and functional characteristics of the system under study.

At this stage, the main subsystems and the functions and interactions between them should be considered. Understanding the system and the levels of information exchange in the system is essential to identifying hazards. Many people make mistakes at this stage because they think they know enough about how the system works. What matters is not exactly how the system works, but also the environment and operating conditions.

• The term system refers to the integrated integrity of something that performs a specific function and includes Hardware, software, human and environmental factors in which the system works.

• A system of combining action consisting of humans, materials, tools, machines, software, facilities, and instructions, assembled for a common purpose in a specific environment.

2. Identify hazards and their causes 

The second step is to identify the dangers and the reasons for their occurrence.

It is necessary to enter the system step by step and identify everything related to the system’s dangers and subsystem under different conditions. At this stage, hazards and adverse events are identified, and the reasons for these hazards are identified.

Risks can be divided into seven general categories:

  1.  Factory and equipment hazards (Mechanical hazards, electrical hazards, generator, transmission, and… )
  2.  Dangers of materials and objects
  3.  Dangers related to the workstation
  4.  Workplace hazards
  5.  Risks associated with working methods
  6.  Risks related to work organization
  7.  Other types of danger

In general, the types of threats in the workplace are:

1. Safety hazards

2. health hazards (occupational health (

3. environmental hazards

Identify hazards

The first and most crucial step in risk management is identifying all the risks that we face in the organization, which is a reliable way to determine the hazards that can lead to significant damage in the organization if not controlled.

Some methods of identifying hazards can be listed in two phases as follows. 

The following two steps need to be taken to identify the hazards:

The first phase includes the preparation and study of the following:

1. Layout of Workplace

2. Operations Chart

3. Description of processes

4. Classification of Jobs

5. List of Material Equipment

6. Work procedures and worksheets

The second phase involves the use of methods to identify hazards:

1. General workshop method)Walking – Talking – Thronging Method (

2. Checklist

3. Job Safety Analysis

4. Accident and Incident Report

5. Work Compensation Claim Report

6. First Aid Statistical Report

7. Minutes of the Joint Health & Safety Committee Minute

8. Previous Inspection Report Previous Inspection Report

9. Supervisors Information about Hazards Foreman Information about Hazard

10. Medical Examination Records

11. Results of Measurement and Monitoring Results of Measurement and Monitoring

12. Hazard & Operability Study (HAZOP)

13. What if (WIF) What if

14. Fault Tree Analysis

15. Critical Task Analysis Technique

16. Error analysis technique and its effects )FMEA(

3. Risk Assessment 

The third step is risk assessment.

Once the risks and their causes have been identified, the risks and their effects must be assessed and analyzed. Most risk analysis methods use some form of severity classification. This classification is used as a symbol to compare the degree of danger with another. In risk assessment, risk severity is determined; the probability of the event’s occurrence is selected; accepting the risk or eliminating and controlling the threat is made.

4. Risk control 

The fourth stage of risk analysis is to take control and corrective measures.

The last step is to evaluate the effectiveness of control programs.

Once hazards have been identified and assessed, appropriate control tools should be developed and implemented.

The risk assessment process deals with identifying and classifying risks. Risks that are “controlled” do not require duplication or new activity. But “uncontrolled” risks need action to bring them within control.

Risk controls are plans or strategies that reduce risks to an acceptable level. The risk level is in the severe, high, and moderate zone; control measures are needed to minimize or (eliminate the concern) risk.

Preventive measures reduce the likelihood of an event occurring and are the best option for high risks.

Emergency measures reduce the impact or severity of what is happening. We often use conditional measures where anxiety (risk) has a high impact and low or moderate probability. Preventive measures are usually more cost-effective.

Types of managerial interventions

According to the steps of risk identification and assessment, there are three basic approaches to risk control.

Which include:

Risk elimination approach (get rid of it entirely (

Reduction of risk (reduction of its severity (

Reduction or mitigation of risk (reduction of exposure to gradual decline (

In general, control measures are divided into three areas:

• Engineering controls

• Administrative and executive controls

• Use of personal protective equipment

2- Methods of analysis and risk identification

Types of risk assessment methods

  • Industrial Risk Assessment
  • Occupational Health Risk Assessment
  • Environmental Risk Assessment
  • General Risk Assessment
  • Financial Risk Assessment
  • Reliability Risk Assessment

Methods of risk analysis and identification

2. Qualitative risk analysis: In this Method of words with descriptive expressions to show the magnitude of the consequences, Possible and the probability of their occurrence are used. These scales can be tailored to the situation, and different words can be used for other risks. This analysis prioritizes for

Provides various purposes, including further research. This analysis is instrumental when

Reliable information is not available for quantitative methods.

1. What-if analysis

2. Checklist analysis

3.What-if / checklist analysis

4.Hazard and operability study (HAZOP)

5.Failure mode and effects analysis (FMEA)

2. Semi-quantitative risk analysis

In semi-quantitative risk analysis, numbers are assigned to qualitative scales such as those used in the qualitative Method, will be given. The goal is a more accurate and complete prioritization of risk. Dimensions other than probability and the possible outcome may depend on the purpose. In some cases, consideration of exposure is critical in the analysis.

Health and safety risks are the number of times a person can be present in an unintended event,

given the task’s repetition and the number of people doing it. Confrontation is important when

Consider several different workgroups or charges. The following is an example of a consideration method

Exposure, probability, and outcome are presented, which is a semi-quantitative method.

• Factors affecting the choice of risk assessment method

• The reason for risk assessment

• Type of results required

• Type of resources available and accessibility

• Complexity and size of risk assessment

• Type of system activity

• The type of events desired

• Extent of required information results

• The amount of expertise needed to apply the selected Method

• Effect of potential consequences

Determining the amount or level of acceptable risk is not done by technicians and risk calculators but is the management department’s task. In other words, the organization’s senior manager must determine the amount of risk acceptance in the organization.

The amount of acceptable risk depends on a variety of issues, including social, economic, and technical capabilities, time, and که, which are summarized here:

Social issues

Nowadays, they scientifically seek society’s opinion about the acceptable amount for different risks and then determine this amount.

Different societies have different cultures and have different views on other risks, and the amount of acceptable risk for them is additional.

Economic issues

Suppose a budget is needed to reduce a particular risk economically that the organization cannot provide. In that case, it will not choose a lower level of acceptance and will inevitably accept the higher risk.

The management system, which is well aware of the organization’s economic capabilities, decides whether to reduce the level of risk or not.

Technical abilities

Suppose it is assumed that there is no technical ability to change and replace the technology available in a factory-like Bhopal in a country like India. In that case, that country will not be able to reduce its risk using the technology available in the factory. It will be forced to keep the technology Old existing continue to use.

Temporal abilities

Whenever the time required to reach a goal is short, we do not have time to search and research the less dangerous ways and then decide; we will be forced to choose the fastest route and take a high-risk level. Therefore, time is also significant in deciding to select or determine the level of risk.

Risk control

Risk controls are plans or strategies that reduce risks to an acceptable level. Where the level of risk is upstairs, they need control measures.

Control measures should be applied first to the probability parameter and, in the next step, to the intensity parameter.

In some cases, control measures must be specified for both parameters.

How to decide on risk control according to the risk assessment matrix:

Once the matrix has been drawn for known hazards, and the level or amount of acceptable and unacceptable risk has been determined, all dangers in the matrix’s inappropriate area should be offered control measures so that the management system can decide accordingly.

For each risk, more than one solution is usually proposed to control or reduce the relevant risk. The management is free to make decisions and can decide on one or more proposed solutions according to their capabilities and work abilities.

Important note:

It is essential that before taking any risk reduction measures, they should be re-evaluated to determine how much the reduction has been and whether it is within expectations and acceptable.

After implementing these solutions, the shape of the risk matrix changes, and the number of risks in the unacceptable risks section is continuously reduced.

 Hierarchy of control measures

To take control measures for unacceptable risks, the following order of control measures should be considered:

1. Delete – Elimination:

The first option is generally to eliminate the risk, such as removing lead, asbestos, and benzene from the production cycle. Unfortunately, risk elimination is not always possible, and its proposal should be considered and reviewed by the Hazard Identification Committee. If it is not possible to delete, we go to the next option.

2. Substitution:

If the risk is not eliminated, less risky methods, equipment, or materials should be replaced. For example, replacing benzene with toluene or using 110 volts instead of 220 volts.

3. Engineering controls:

In situations where it is impossible to remove or replace, engineering controls are used to control the risk, such as protecting devices, earthing systems, design and installation of the local ventilation system, etc.

4. Signage / Warnings and Administrative controls:

After performing the measures mentioned above, to observe the safety points, management controls will be implemented, such as installing warning signs, installing safety instructions, and holding training courses.

5. Personal Protective Equipment:

The use of personal protective equipment is recommended as a last resort, and in some cases, in addition to the above measures, it is used to increase the safety factor.

Ways of risk identification and risk assessment:

Today, the use of risk identification and risk assessment methods is expanding in various industries. There are more than 70 different types of qualitative and quantitative risk assessment methods and techniques in the world. These methods and techniques are usually to identify, control, and reduce the Consequences of risks apply. The main risk assessment methods are appropriate methods for risk assessment, and their results can be used to manage and decide on control and reduce its consequences without worries. Each industry, depending on its needs, can benefit from these methods. These methods have different advantages and disadvantages over each other.

Therefore, one of the existing safety and health management systems in each industry (HSE) is to review all risk and hazard assessment methods and select the appropriate way to be implemented in the industry and its organization.

Quantitative methods

In the quantitative Method, The probability of a particular accident and its consequences is calculated or estimated. Then the obtained numerical criterion is used to judge the acceptable risk. Numerical estimation is difficult to perform and usually requires specific tables to convert qualitative values ​​into quantitative values ​​according to risk assessment and weighting techniques.

• Qualitative methods

In the qualitative Method, values ​​are usually expressed by using less, more, average, dangerous, intolerable, etc. Its use is more and more comfortable. But if the risk assessment system’s output is small, everyone’s perception of the situation is closer, and the results will be more useful for decision making.

The following is a summary of some of the methods used to identify hazards and assess risk.

Job Safety Analysis Technique

JSA is one of the methods of accident prevention and risk analysis with a long history of use.

JSA is a systematic review of a job to identify its potential risks and determine the appropriate control method.


One of the essential JSA implementation goals is to find practical and efficient approaches in integrating the human element with design and operations to achieve higher levels in the field of safety, reliability, efficiency, and…

Job safety analysis is a job review, not a job.

JSA involves analyzing critical job tasks to identify potential hazards and identifying safe ways to do so.


• JSA steps:

First step: Select the desired job for analysis:

Ideally, all positions in any organization should be studied by the JSA. However, this may not be possible due to various constraints such as resources and time, so existing jobs should be listed and prioritized using the following parameters.

The most critical factors in the job prioritization process for implementing JSA:

1.Statistics of accidents and diseases –

2.Absences from work –

3.Signs of exposure to harmful elements –

4. severe consequences –

5. jobs changed –

6. non-routine jobs –

Second stage: breaking the job into constituent tasks

Typically in any position, a person has several responsibilities. Each of these tasks can have its risks.

Dividing a job into its tasks requires having sufficient and complete knowledge of that job. If functions are selected in a very general way, specific operations and associated risks may be forgotten.

Third step: Identify the steps of performing a task

The actions of conducting the study are identified and recorded in the order of its execution.

To identify its steps, you can film how the operator performs the activity.

Fourth step: Identify potential hazards in each step

At each stage of a task, all possible risks are identified.

Fifth Step: Determine preventive measures to control identified hazards

We recommend corrective and preventive measures by prioritizing control measures.

sixth Step: Notify employees

The correct steps to perform an activity and the identified hazards, and the necessary control measures are formulated in safety instructions and communicated to employees.

Sample Occupational Safety Analysis Form (JSAJSA)

• Advantages and advantages of JSA technique

1. Identify occupational hazards –

2. Develop the best way to do the job –

3. Improve efficiency and productivity –

4. step-by-step tutorials for doing a job –

5. Reduction of injuries and injuries caused by effort b Too much –

6. Determine the tools and equipment needed to do the job –

7.Participation of people and the possibility of using their experiences –

8. partnerships lead to acceptance

9. resistance to the subject decreases

10. makes it easy to work

11. increases work speed

12. duplicate tasks are prevented

13. decision coefficients are reduced

14. creates a cheerful personality in the person

15. saves time

16 – …

Essential points about JSA:

JSA is a risk identification method. Another method should be used to assess the risk.

JSA is excellent for preparing safety instructions.

William Fine Technique 

In this technique, considering the costs, corrective measures are proposed to control the risks. One of the characteristics of this Method is the involvement of costs to check the justifiability of controls.

Intensity (Consequence)

Probability R = C * P * E ​​Risk rating


Risk rating (R) is used to prioritize and classify risks.

After calculating the risk, the following formula is used for a justifiable cost.

J = R / (CF * DC)


Cost factor CF = COST FACTOR

Degree of correction DC = DEGREE OF CORRECTION VALUE

From the above formula, it can be concluded that by dividing the risk rating by multiplying the cost coefficient and the degree of correction, it is possible to calculate the cost’s justifiability to reduce the risk. The criteria used are contractual decisions. For example, the following mode can be used:

J> 10

The cost is justified.

J <10

The cost is not justifiable.

Using this technique, finally, the risk number is obtained using the obtained factors for the severity, probability, and degree of risk exposure. Using the mentioned coefficients, its economic justification is examined.

Preliminary Hazard Analysis (PHA)

This method was first used in the United States in the early 1950s to analyze liquid-propelled missiles’ safety. This Method was legalized by the country’s aviation industry and was named by Boeing under its current name. After this application, this technique spread to various industries, including chemical, nuclear and other industries.

Preliminary risk analysis is a semi-quantitative analysis method that is performed for the following purposes:

Identify potential hazards and unexpected events that may lead to an accident. –

Classification of identified events according to their risk –

Determine the necessary controls for risks and remember corrective actions -Preliminary risk analysis is preferably a preliminary safety analysis of the system, product, or organization.

 its main objectives are:

• Identify the elements, dangerous conditions and their causes

• Identify the effects of these elements and hazardous conditions on subsystems, systems, the entire project

• Classify the level of severity of each component and dangerous conditions

Identify corrective actions to eliminate hazardous elements and conditions or minimize their effects. PHA-derived data is a useful and practical input for other safety activities to identify the following:

• Potentially problematic areas related to Hardware, software, or their common denominator;

• Standing requirements or safety design,

• Prioritize safety activities,

•  Items that require testing, further analysis or balance studies,

The technique of analysis of potential failure situations and their effects

Analysis Failure Modes & Effects (FMEA)


First used by the US military in 1949.

*The first official use of this Method was in the American aviation industry.

*This Method was first introduced as a tool to prevent irreparable mistakes and errors


*This technique is now part of US military standards and is called MIL-STD-1629

*FMEA is an engineering technique to identify and eliminate potential errors, problems, and mistakes

The existing system is the process of producing and providing services before it occurs.

• This approach seeks to maximize the potential risks in the area where the risk assessment is performed.

Identify and prioritize the causes and effects associated with those risks.

The benefits of performing FMEA are:

1.It is an excellent tool to prevent dangers.

2.There is little suitable Method for risk assessment.

3. It is a reliable way to identify hazards caused by devices, equipment, and machinery.

MFMEA steps

1. Data collection –

2. Identification of hazards (safety + occupational health) –

3. Determining the effects of each hazard –

4. Determining the Causes of Each Danger –

5. Review of existing control measures

6. Determination of the intensity factor

7. Determining the probability of occurrence

8. Determining the risk detection coefficient

9. Calculate the risk priority number) – RPN = Risk Priority Number

10. Risk Acceptance Decisions

11. Provide Proposed Remedies for Unacceptable Risks

12. Recalculation – RPN = Residual risk

The difference between FMEA and other qualitative techniques

FMEA is a tool used with the least risk to predict problems and defects in the design or development of processes and services in the organization.

This technique is designed to be “an action before the event” and not “an exercise after the problems are revealed.” In other words, one of the fundamental differences between FMEA and other qualitative techniques is that FMEA is an action, not a reaction. In the implementation of FMEA, by anticipating potential problems and calculating their risk level, measures to eliminate or reduce their occurrence are defined and implemented. This preventive approach is an action against what is possible to occur in the future. Indeed, take action correction in the early stages of product or process design will cost much less time and effort.

Also, any changes at this stage to the product or process design are easily made, thus eliminating or reducing the need for critical differences in the future.

FMEA operates in any of the following conditions:

1. When designing a new system, new product, or new process.

2. When existing designs or the production/assembly process is to take place

3. When the production or assembly processes or a product is placed in a new environment or new working conditions. Carry Over Designs / Processes

To complete the FMEA, the team must provide complete answers to the following questions:

A. Under what circumstances can the product not meet the design goals and objectives or the process’s needs cannot be met?

B. What effect will failure situations have on the customer? –

C. What is the severity of the failure effect? ​​(Severity number)

D. What are the potential causes of failure?

E. What is the probability of the causes of failure? (Number of occurrences)

F. What controls are currently being performed to prevent or diagnose malfunctions and their motivations?

G. What is the detection power of the existing controls? (Detection number)

H. What is the risk of potential failure situations for various reasons? (Calculation – RPN)

RPN or Risk Priority Number means the risk priority score.

Severity = × Occurrence × RPN detection risk priority score

Benefits of FMEA

Increasing competition, increasing expectations, frequent customer demands, and rapid technological changes have led to a rapid increase in today’s manufacturers’ obligations. Any shortage and deviation in product performance lead to market loss. These factors have led organizations to Use this technique to make sure they launch flawless and competitive products.


Sample FMEA form

Name of workshop:

Evaluator Name:

Evaluation date:

Reassessor name:

Re-evaluation date:



the danger

Danger effects

Cause / causes

Existing control measures

Evaluation 1

Existing risk

Proposed control measures

Evaluation 2

Risk again



Discover / control





Discover / control



Residual risk outcome




The severity and probability of occurrence provide a good indicator for determining risk priorities. The lower the probability of occurrence, the more acceptable the risk. And the lower the financial and human consequences of an accident, the lower the severity index and the lower the absolute risk.

The following are some crucial measures in terms of prioritizing activities and effectively reducing the severity and likelihood of an accident.

Change in design


*Use of safety equipment in the system

*Risk acceptance

*Complimentary evaluations, more complete studies, and application of complementary methods

Usually, a unique method is not used to control and eliminate the causes of the accident. According to the evaluation results, different ways are used to solve the problem and improve the situation.

Implement safety measures and follow up evaluation

Safety programs strive to achieve 100% reliability as close as possible, and after implementation and by reviewing and evaluating the outputs, continuous improvement measures are taken to improve.

HAZOP technique

Definition of HAZOP: HAZOP is a qualitative method for identifying process, human, and machine hazards.

ZHAZOP Identifies and analyzes deviations related to the performance of parameters with the help of keywords.

This technique identifies hazards using a team of experts and brainstorming.

Begins and seeks to discover the causes and effects of potential hazards.

There are generally four types of HAZOP.

Types of HAZOP


1.Process :

• The general procedure of this type of HAZOP relies on reviewing processes and flow diagrams and how to use devices and equipment. It then divides the study system into simpler components and tries to identify process deviations using guidelines…

2 – Human :

It is a particular type of HAZOP that focuses more on human errors (than technical errors). This type of HAZOP is based on task analysis. Input information for this type of HAZOP Events work is the workstation’s location and issues related to the human-machine relationship.

This type of HAZOP covers the following errors:

• Errors related to the design and use of tools and computers

• Errors associated with determining the role of the worker and his work competence in the system

• Errors related to labor and human relations.

3 – Procedural:

: This type of HAZOP reviews procedures and operational sequences

put. HAZOP procedures focus on both human error and technical systems.

4 – Software:

This type of HAZOP is used to identify potential errors in software development.

HAZOP Objectives:

• The following goals can be considered.

. Identify all potential causes that lead to significant safety and operational effects in the study area.

• Decide whether existing designs ensure that the risk of known hazards is at an acceptable level.

• Achieve an acceptable level of risk.

• • Maximizing the value of facilities in the company by reducing the risk of processes related to an acceptable level and improving operational efficiency.

Steps to perform HAZOP

• Start:

Certainly, before starting HAZOP, suitable grounds should be provided, including:

• The commitment of senior management to provide the necessary resources and support.

• Accredit the work of group members – HAZOP by identifying them and giving the required authority to the group.

• Support group decisions to implement proposed actions.

• Available

Insert the required resources, including maps, diagrams, plans, and technical information necessary for the process.

• After ensuring the creation of a suitable background, the HAZOP team should be formed.

The team is centered on the group leader.

• Studying HAZOP requires a trained leader.

• Members of the HAZOP group:

• Group members must have received the necessary training to study HAZOP.

• Group members must have the ability to understand the potential risks of the process and the industry-standard methods to control this

Have risks.

• At least one member of the group must be responsible for obtaining information from past incidents (in similar facilities) and follow up on essentials.

• Check technical documents and information in HAZOP:

 Documents required for review include:

• Operation description (Operations events and diagrams)

• Describe the use of tools and designs of operational equipment

• Documents related to installation, commissioning, and maintenance of devices

• Inside and outside environment information such as temperature, humidity, pressure, weather conditions, floods, earthquakes, and.

Check technical documents and information in HAZOP:

• The team leader should ensure that all processes in the area under study are technically reviewed

have become. It must also provide the validity of the information and incomplete and invalid information of the case

Do not check. If part of the process is to be set aside, it must be agreed upon by the members

And the reasons for it should be recorded and reported to the top management.

Divide the system into smaller parts:

• Processes and devices should be broken down into smaller pieces for review and analysis. This

Segmentation should not confuse group members with the use of keywords.

• The group should also decide on the details of the processes and activities according to the study’s objectives and time.

To determine the level of detail required and appropriate to the objectives.

• Subsystem selection:

• According to the leader and team members’ knowledge of the process, subsystems are based on a sequence of operations and importance

Processes are selected. Each subsystem must be accurately identified and introduced to all members.

 Parameter selection:

• Parameters are essential because we can analyze their deviations from the design. So

Important parameters should be sought. The importance of parameters by analyzing and recognizing individual group members

Turns. These parameters are naturally different in different industries.

• The group must document the set of parameters by agreement. For example, in most oil companies and the following parameters are used in chemicals with continuous processes.

Select keywords: (Guide Word)

• The selected keywords should be tailored to the critical process parameters (such as flow, temperature, pressure, etc.) and other system operations (such as turning the device on or off, testing, maintenance, etc.)

• The following are examples of the HAZOP process and human and procedure guidelines:

• HAZOP Process Keywords:

• Human HAZOP guide words:

• Handwords for HAZOP Procedure:

Steps to perform HAZOP:

• Determine parameter deviations:

• Combining each keyword with each parameter forms a departure. The variation of the value

was designed. The important thing here is to make sure the existing design is correct. So it should be with

Use documents and information to ensure that the current system is acceptable.

• Impacts should be specified in the objectives of the HAZOP study. But HAZOP is a qualitative method, and from this, it relies entirely on the analysis and knowledge of the group members.

• If due to incomplete information, it is impossible to decide on the significance of the effects, additional measures should be taken to resolve this ambiguity. These actions must be documented and reported.

Suggest corrective action:

Corrective measures should be aimed at eliminating the cause, reducing the deterioration, reducing the incidence of the reason, and job satisfaction. Also, the person responsible and the time of reviewing the intended measures should be specified. These actions should be reported to senior management for importance.


• If the review of all keywords and parameters in each case is completed, we move on to the next items.

• But it should never be considered over. The team leader must continuously strive for continuous improvement of the HAZOP process. Computerization of the technique for faster and more up-to-date access to information by members, more attention to brainstorming activities, use of checklists for possible causes of problems, attention to human factors, and help management make better decisions to improve the HAZOP process continuously.

HAZOP checklist

• Checklists can usually vary depending on the type of industry being studied. But the following example can be an almost comprehensive case of HAZOP checklists.

• Important point: Filling in the HAZOP checklist should be made horizontally; that is, after determining the deviation and the effects, we should evaluate its causes and complete the HAZOP study for each reason.


Before the meetings are held, the criteria related to the time, place, and participants must be determined and in

Specify the HAZOP procedure.

• It is the group leader’s authority to postpone meetings or even a study if one of the group’s leading members is absent until that person returns or a replacement is considered.

• One of the people present at the meeting is the group’s secretary, who has the following duties.

• Prepare HAZOP sheets

• Register discussions in HAZOP meetings

• Prepare a draft meeting report

• HA The agenda of the HAZOP meeting can be as follows:

• Introduce and introduce members and other participants

• Provide general information to temporary participants about HAZOP and its objectives

• Review past corrective actions and follow up on its status

• Provide the operation or node to be studied by HAZOP.

• Analysis of operations with the stated Method

• Summary of evaluated items

HAZOP report:

The quality of the HAZOP report depends on the skills of the members. However, statements should be based on HAZOP meetings. The presentation of preliminary results and findings and intra-group agreements should be mentioned in the report

To be. Before preparing the final report, a draft should be given to the members, and after reviewing and providing explanations, the final report should be prepared.

Benefits of HAZOP:

• Being innovative in what system to choose for study and which parameters to focus more on offers different HAZOP results.

• A complementary method to identify all possible risks

• Using keywords helps to strengthen the mental storm.

• Strengthen the understanding of the need for safer work methods and better practical training and how to express them.

Disadvantages of HAZOP:

• If we want to examine in more detail, we have to spend a lot of time.

• Based on people’s knowledge

. This system’s nature requires that process specialists often be involved in completing the HAZOP tables and does not include most of the people involved in the work, including operators, supervisors, and simple workers.

• Lack of risk classification due to lack

• No slight prioritization is foreseen in this system. Therefore, FMEA is considered as a more advanced model of HAZOP. The diversity of causes and effects may reduce the accuracy required for the more important causes and effects of the error. Document number:

Review Date:


Name of the person reviewing:

Human HAZOP example:

Consider a furnace operator. The operator’s job is to regulate the pressure and temperature inside the furnace. The operator must also fill a metal-containing plant to the tune of one ton and direct it into the stove. The weighing is done by a weighbridge adjacent to the furnace. After 30 minutes, the operator must adjust the furnace pressure and remove the plant. The purpose is to investigate the operator’s deviations from the assigned task with the help of the HAZOP method.

• Study: – Case – Time ———————————————— Furnace – Operator -: Study – Case – Person

ZHazop procedure:

Instructions for storing barrels containing thinner are prepared as follows:

1. Stack barrels up to three rows

2. Keep the barrels at the desired temperature

3. Identify barrels by writing the word thinner on barrels


In general, it can be said that the type of Method used in risk assessment and the depth of its review can, to some extent, understand the ability of the existing safety system and thus safety management in the industry.