Introducing the five methods of risk assessment, each of these methods has its own strengths, each has its own weight, for different risk identification objects, can be used flexibly, or specialize in one, or a combination of several, the main consideration should be its effectiveness and acceptance of employees, the ultimate goal is to accurately identify all the possible risks of value for the subsequent risk assessment and risk control to provide a reliable basis.
1 On-site Observation method through on-site observation of the work environment, to find the existence of the source of risk by finding the site of hidden danger, the scope of adaptation is broader.
Advantages: the site observation method applies to all places and operations; disadvantages: ① personnel engaged in on-site observation, required to have safety and technical knowledge and mastered the perfect occupational health and safety regulations, standards; ② not adapted to the observation of a large area.
2 safety checklist method SCL: it is by some of the process, machinery and equipment and operating conditions are familiar with and rich in safety technology, safety management experience, according to the relevant norms, standards, processes, systems, etc. Prior to analyzing the object of exhaustive analysis and full discussion of the contents of the checklist and check points and prepare a table. Based on on-site observation, reading system documentation, talking with operators, and personal understanding, the analysts answer the questions listed in the safety checklist to find discrepancies between various aspects of the system design and operation and the standards and regulations, and then write down the discrepancies.
Advantages: the safety checklist is the result of qualitative analysis, is based on the original safety inspection, easy to learn, easy to grasp, especially for the post staff to identify hazards, to play a good role in prompting, to facilitate the comprehensive identification of hazardous factors. Disadvantages: checklist constraints limit the play of people's supervisory initiative, the problems that are not reflected in the checklist may be ignored, therefore, the use of this method may miss some new hazards that have not appeared in the past.
Scope of application: Safety checklists are generally applicable to more mature (or traditional) industries, the identification of hazards in the field, and the need to prepare a checklist in advance to identify against. Safety checklist method is especially suitable for front-line employees to identify hazardous factors, such as, before the start of operational activities, or the inspection of equipment and facilities, and so on. Can only have or traditional business objects, activities to check, for new business activities, new industry areas of hazardous factors identification does not apply to this method.
Hazard identification checklist used with the safety inspection checklist is not exactly the same, they are roughly the same, but each has its own focus, therefore, should not be used directly to identify hazardous factors used in the safety inspection form checklist should be modified on the basis of its supplement, it is best to re-development.
3 Preliminary Hazard AnalysisPHA: Preliminary Hazard Analysis, also known as Preliminary Hazard Analysis, is to carry out a project activity (including design, construction, production, maintenance, etc.) before the existence of a variety of hazardous factors in the system (category, distribution), the conditions of emergence and the possible consequences of the accident. Macro, general analysis of the consequences of the system safety analysis method.
Advantages: In the initial conceptualization of product design, you can point out the existence of the main dangers, from the beginning can take measures to exclude, reduce and control them, to avoid losses due to ill-considered. In the huge, complex system hazard identification, you can first analyze and judge the main dangers of the system through the advance risk analysis, so as to carry out in-depth analysis of the main risks in a targeted manner. Disadvantage: It is easy to be influenced by the subjective factors of analysts. In addition, the advance risk analysis is generally a general analysis, can only provide preliminary information, and the degree of accuracy is not high, complex or high-risk systems need to be based on this, with the help of other methods to do further analysis. PHA can only provide preliminary information, is not comprehensive enough, and can not provide detailed information about the risk and its best risk prevention measures.
Scope of application: PHA is generally used in the early stage of project evaluation to filter some low-risk links and areas through PHA, and at the same time, it also creates the conditions for further in-depth hazard identification by other methods in other high-risk links and areas. Applicable to the inherent system to take a new approach, exposure to new materials, equipment, hazard evaluation. PHA can also be used to analyze completed installations when only a cursory analysis of hazards and potential accident situations is desired.
4 Job Hazard Analysis JHA: Job Hazard Analysis (JHA), also known as Job Safety Analysis (JSA) is currently the most common type of operation used by European and American companies in safety management. Safety analysis and control of management tools, is to identify and control the operational hazards of preventive work processes. Through the step-by-step analysis of the work process, its redundant and hazardous work steps and work equipment/facilities are identified, and control and improvement measures are formulated to achieve the goal of controlling risks, reducing and eliminating accidents.
Advantages: The method is simple, clear and easy to understand, especially now that the JSA/JHA method standard has been developed, which is operable and easy to implement. So that the operating personnel more clearly recognize the risks of the operational process, so that preventive measures more targeted, operable. Disadvantages: The method does not have much advantage in hazard factor identification, it is not a specialized method recommended for hazard factor identification, but due to its simplicity and operability, it is generally used for risk management of non-routine operational activities.
Scope of application: Job Hazard Analysis is generally used in operational activities such as risk management of new operations, non-routine (temporary) (including, of course, hazard identification), or when evaluating existing operations, changing existing operations. Job Hazard Analysis does not apply to the identification of hazards for continuous processes and for equipment, facilities, etc.
5 Failure type and impact analysis FMEA: Failure type and impact analysis is in the product design process, through the product of the various components of the unit of the potential types of failures and their impact on the function of the product is analyzed. And each failure according to its severity to be categorized, put forward can be taken to prevent, improve measures to improve is the work of the system are divided into subsystems, equipment or original, one by one to analyze the type of failure that may occur in each of them and the impact, in order to take appropriate measures to prevent and control, to improve the safety of the system.
Advantages: systematic presentation tool; creates a detailed and auditable hazard factor identification process; broader applicability, widely applicable to manpower, equipment and system failure modes, as well as hardware and software.
Disadvantages: the method only considers individual failure scenarios and does not allow for the integration of these failure scenarios; the method relies on the involvement of professionals who have a thorough understanding of the system or device; and the method is time-consuming and costly.
Application: Failure type and impact analysis is widely used in the manufacturing industry in all phases of the product life cycle, especially for the product or process design phase of the identification of hazardous factors. If you want to do a good job of identifying the hazardous factors of operational activities need to refine the steps of the activity, then, the hazardous factors of the equipment and devices should be identified to refine its functional unit, on this basis, in order to do a good job of identifying the hazardous factors of the equipment and devices, the FMEA method is the example.