Safety Analysis Work Methods

Safety analysis is completed when weak points have been identified and when proposals for their neutralization (elimination by suitable measures) have been made. The sections which follow explain the equipment for execution of safety analysis and provide examples for practical procedure. 

Safety analysis uses logic structure representative of possible incidents. Such work methods as fault tree, incident analysis, and decision table are suitable for this purpose. Computation rules for determination of expected frequency of incidents must be formulated accordingly. In a broad sense all mathematical simulation methods which are suited for determination of stress states in technical installations and their parts become aids in safety analysis. These will be described in partial detail later. Here characteristic work methods which are of direct significance with respect to system-related and prognostic consideration of safety analysis will be discussed first, 

Concept of Probability and Rules of Computation. The definition of probability is determined as application-oriented. Logic difficulties resulting as compared to exact mathematical definition on quantity-theoretical basis, can be ignored in the present context. If A is the designation of an event as the result of an experiment with clearly described objects under 

Here N is the total number of experiments and N A) is the number of experiments with the result A as incident. The incident probability is the boundary value of relative incident frequency w hen the number of experiments moves toward Incidents in this sense are, for example, the function or malfunction of a safety installation or its components, a specific failure in a technical system as a result of a trigger event, the appearance of manufacturing errors of a specific nature in the case of specific products, or the observance or nonobservance of boundary values as well as various conditions in general of the object under observation. Probabilities can assume onlv values betw een 0 and 1. so that 

If is a further incident, the conditional probability W A B) for the occurrence of A on the secondary condition that B occurs as well can be 

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From this analysis it appears that a huge discrepancy exists between deviations prior to accidents, that can be found in normal operation and the pro-active safety indicators and methods in current use. The re-occurring indirect safety related deviations that are the dominant class of events causing accidents are therefore defined as the precursors for accidents, as stated in Chapter 1. Furthermore, from Table 5 it can be concluded that a clear link between risk reduction and the normal way of working is not explicitly present in one of the three methods. Finally, the feasibility of methods (except PRISMA) needs some attention additional expert knowledge is often necessary to apply the method. The focus of the method indicating safety risks developed in this thesis will lie especially on these three criteria. 

The human factors literature is rich in task analysis techniques for situations and jobs requiring rule-based behavior (e.g., Kirwan and Ainsworth 1992). Some of these techniques can also be used for the analysis of cognitive tasks where weU-practiced work methods must be adapted to task variations and new circumstances. This can be achieved provided that task analysis goes beyond the recommended work methods and explores task variations that can cause failures of human performance. Hierarchical task analysis (Shepherd 1989), for instance, can be used to describe how operators set goals and plan their activities in terms of work methods, antecedent conditions, and expected feedback. When the analysis is expanded to cover not only normal situations but also task variations or changes in circumstances, it would be possible to record possible ways in which humans may fail and how they could recover from errors. Table 2 shows an analysis of a process control task where operators start up an oil refinery furnace. This is a safety-critical task because many safety systems are on manual mode, radio communications between control room and on-site personnel are intensive, side effects are not visible (e.g., accumulation of fuel in the fire box), and errors can lead to furnace explosions. 

In addition to the literature on job analysis, there is also a body of work which has focused solely on methods for identifying the hazards and risks associated with a job. As some examples, techniques such as job safety analysis, also referred to as job hazard analysis (Chao and Henshaw 2002), construction job safety analysis (Rozenfeld et al. 2010), and constmction hazard assessment with spatial and temporal exposure (Rosenfeld et al. 2009) have been extensively discussed. These techniques are very useful for safety management, and among other things can be used to generate safety-related information which can be used to determine the essential knowledge, skills, abilities, and other characteristics which are required to perform the job safely. 

Job Safety Analysis (JSA) is a formal method that can be used to identify, analyze, and record the steps of a job in order to identify the safety hazards and avoidance methods. Although this topic was already addressed in Chapter 4, it is important to restate the value of this tool here. JSAs are the perfect employee engagement tool with which to build safety awareness. Using a prescribed method and standard forms, work team members evaluate the very work they perform to identify any safety hazards. It is a safety kaizen activity. 

JSA Job safety analysis is a detailed review of the safety steps related to a particular work task. The steps are recorded on a standard form that can then be used to train individuals in the best practical safe way to perform their work tasks. This is a proactive method that can help to develop a world-class safety culture. 

Lamvik, G.M., N sje, P.C Skarholt, K. Torvatn, H. 2009. Paperwork, management, and safety Towards a bureaucratization of working life and a lack of hands-on supervision. In Safety, Reliability and Risk Analysis Theory, Method and Applications. Martoell et.al, (eds). London Taylor and Francis Group. 

Forseth, U., Torvatn, H. and Kvernbeig Andersen, T. 2009. Stop in the name of safety - The right of the safety representative to halt dangerous work. In Martorell et al. (eds.), Safety, ReliabiHty and Risk Analysis Theory, Methods arui Applications. London Taylor Francis Group. 

A safety management risk assessment techniqne that is used to define and control the hazards associated with a process, job, or procedure. The Job Safety Analysis ensures that the hazards involved in each step of a task are reduced to as low as reasonably practical (ALARP). The assessment starts with a summary of the entire job process. The job is broken into smaller steps and listed in a tabular form. The hazards for each step are then identified and listed. This is repeated for each step in the process and a method of safe work is identified. It may be also called a Job Hazard Analysis (JHA). See also As Low As Reasonabfy Practical (ALARP). 

It cannot be overemphasized that the principal elements of a sound industrial safety program, with its primary purpose of OSHA compliance, work hazard reduction, assurance of employee/job safety and health, and the evaluation of jobs or tasks (through the ISA or another comparable method), can, in most cases, be achieved through application of the system safety process. The connection between the two programs, while not entirely obvious, is quite understandable, as described above. Perhaps the most important thing to remember here is that the industrial or occupational safety and health professional can utilize the time-proven techniques of hazard reduction and system safety analysis to accomplish the desired goal of both programs ... 

One may have sufficient data to apply multivariate analysis. For example, multiple regression analysis may identify the extent to which key dependent factors contribute to accidents, the independent variable. Use of that method may help identify which elements of a program have the greatest impact on safety performance. The methods may also work for leading indicators of safety performance. 

The odier major vantageof the method is the abiliiy to use very detailed cross-section information instead of group-averaged cross sections. While much work is done usii% detailed cross sections, the lack of extensive validation of particular sets of data has thus far.prohibited the use of such data in routine criticality safety analysis. 

In reactor safety studies of this nature, an attenqit is made to construct a table or- plot of accident consequences (isotope amounts released) vs likelihoods. The basis for this work began with Farmer, was continued in studies such as that by Otway and Erdmann, and has recently been utilized by the Atomic Energy Commission, with substantial methods development. A similar approach was used for a reprocessing plant safety analysis for a mixed-oxide fuel fabrication plant, in the transportation of nuclear materials, and in considerations of waste storage. ... 

After a preparation period of one week in Delft, the fieldwork lasts about 3 weeks in Spain. Back in Delft, 2 weeks are allocated for laboratory testing, data analysis and reporting. During the whole fieldwork duration, students share responsibilities and work load. On some occasions, they have to work out conflicting interpersonal/intercultural relationships or working methods to induce efficiency and creativity. At any time, safety in the field is paramount. 

The Job Safety Analysis Process A Practical Approach. The precept behind using JSA/JHA is that fatalities, accidents, and injuries can be reduced by working together and sharing safety knowledge. An accident prevention method that has proven effective in industry is the Job Safety/Hazard Analysis program. 

For moderate-sized locations, I strongly recommend that safety professionals consider drafting and proposing the implementation of a pre-job planning and safety analysis system as the implementation method to fulfill the Management of Change Policy and Procedures drafted to meet the requirements in ZIO. The purpose of a pre-job planning and safety analysis system is to provide a means for supervisors and their staffs to determine how the work is to be done and to study the hazards and risks that may be encountered—before the work commerces. 

The technique of job safety analysis OSA) has evolved from the work study techniques known as method study and work measurement. 

Job safety analysis uses the SREDIM principle but measures the risk (rather than the work content) in each of the component parts of the job under review. From this detailed examination a safe method for carrying out each stage of the job can be developed. 

Safety analysis data input consists of facts and figures on the production process used, on the materials handled, the technical design of the installation, the operations organization, and the environment. The sum total defines the object under analysis. For the analysis proper, systematic representation of the installation with due consideration of safety aspects as well as selection of work methods and evaluation critieria are significant. 

A series of methods [4-17], [4-181, (4-19j were developed for qualitative safety analysis and found to be successful. The choice of the analysis procedure, the special methods included, the application sequence, and the required extent of work depend on the project. The following must be considered ... 

Changes to production methods, procedures, or production standards, shall be reviewed for safety to ensure that the associate performing the work is not placed at risk. Documents relative to those methods or procedures, such as Job Safety Analysis (JSA), shall be revised and communicated to affected associates. Tlie evaluation shall include an Industrial Hygiene review if chemicals are used and an Ergonomic Job Analysis (EJA) if production standards have been modified. 

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