Process Systems Risk Management - Essay Example

INTRODUCTION TO SYSTEM SAFETY AND RISK ASSESSMENT By Name Course Instructor Institution City/State Date Introduction to System Safety and Risk Assessment Preliminary Hazard Analysis Preliminary hazard assessment system is essential in identification of hazards associated with a certain design while the design is in its initial stages. The preliminary hazard analysis identifies the elements of the design that are hazardous and assess the possible measures in preventing the risks associated with the hazardous elements. This analysis looks the design as a big picture of the system in full in a safety perspective. Other analysis system may follow the preliminary hazard analysis (Mannan & Lee, 2005, p.27). The steps involved ion the analysis: Identifying hazard of design Identifying possible effects of hazards Estimating the likelihood of the events Proposing a measure Assess the risk of the measure Recommend good measures Determining the residual threats assuming the proposed measures Sources that are useful in identifying hazards include the component description and history of operating similar designs. The idea of carrying out the preliminary hazard analysis is to assess the risk that a certain project causes on the people, the environment, and the properties of the company. The company deals with machines and instruments that are likely to affect the safety of the people in the company. This improves the safety of the people since it will identify the hazardous elements that are likely to cause a system failure. A failure in the system may result to injuries and possible deaths. The benefits of the preliminary analysis include a safer final product, cost of modifying the design in early stages are less compared to modifications made at later stages of the design and reduces the number of accidents in the company (Mannan & Lee, 2005, pp. 29-30). Fault Tree Analysis This is an analysis technique in which an undesired event which at the top level is analyzed by identifying the causes of the undesired event from the lower level. In this technique, the common question is ‘What caused that?’ in fact the fault event is always identified first and the causes that may have caused the fault event is identified from the lower levels hence forming a fault tree. The immediate causes of each event are identified hence helps in identifying the cause of the undesired event at the top. The fault tree diagram indicates the relationship of the events that resulted in the undesired top fault. Therefore, the fault tree serves as a systematic analysis record of the basic causes that led to the top event (Raman & Cameron, 2005. P. 301). Two categories of events exist in this analysis, which are the basic events and the top events. The top events are linked to the basic events via logical symbols called gates. Top events are the hazards that have been identified while the basic events at the bottom refer to components of a system and human errors. The reasons for carrying out a fault tree analysis are to enable the system engineers identify the causes of certain system failures in the organization. Fault analysis tree also serves in identifying the possible weakness of a system that used in a certain organization In addition, carrying a fault tree analysis resolves the risks caused by accidents, find a system to replace the fault one and optimize test of the systems (Raman & Cameron, 2005. P. 312). Event Tree Analysis This technique identifies the consequences that are likely to occur following an accident. It identifies the sequence of all events that have occurred in an accident scenario and evaluates them. This technique is useful in assessing the effects following a nuclear accident in nuclear industries. The event tree analysis uses an event tree diagram called a visual logic diagram, in determining whether the initial accident will result into other catastrophic events. It is also used to assess whether the initial event is controlled sufficiently by the available safety systems if they are properly implemented in the project. Depending on the quality of the safety system in place, the outcomes of the initiating events may vary. The possible outcomes following an event include injury, loss of lives, mission failure, system unavailability, equipment damage, and environmental damage (Raman & Cameron, 2005. P. 320). Therefore, the visual logic diagram generates the possible outcomes. The aim of an event tree analysis is to determine the probabilities of the possible consequences of the initiating event. These outcomes are useful in determining the desired results and the results that lead to undesirable events. In the engineering company, an event analysis is likely to be conducted when accidents occur. Therefore, the administration should ensure that it adopt the best safety systems that can minimize the occurrence of undesirable outcomes in the event of an accident. The event tree analysis is also useful in assessing safety systems that are in continuous operation or those in standby modes. This helps in minimizing the losses that may result from a complete system halt (Mannan & Lee, 2005, p.30). Failure Mode and Effects (Criticality) Analysis This design technique aims at improving the reliability of a system. This tool determines the possible modes of failure within a system and its components. This is helpful in determining the effects of these modes of failure on the performance of the system. The various modes failures depend on their impact on positive results on the mission and the safety of the people and equipments (Stephans, 2012, P. 79). This analysis tool has two parts, the failure mode effects and the critical analysis part of the method. The failure mode effects analyses on a qualitative approach while the failure mode effect and critical analysis on the quantitative approach. The success and failure of this analysis technique depends on whether the information necessary is communicated in the best timelines (Stephans, 2012, P. 98). The company should have a good understanding of this analysis since it helps the company to be able to establish the modes of system failure and their effects on the performance of the system. The method also is helpful in designing a fault tree analysis, which is also a critical analysis tool in cases of accidents. The technique is useful in identify the causes of certain system failures in the company, hence provides the framework in the formulation of better working solutions. In addition, the failure mode effect and critical analysis tools provides the aids necessary in developing better test methods and techniques for troubleshooting. Therefore, adopting the failure mode effect and critical analysis will help to determine the primary failures in a system hence preventing secondary failures that are costly (Mannan & Lee, 2005, p.57). Hazard and Operability Analysis This technique used in the identification and evaluation of the hazards that are involved in a process. The technique identifies problems that have the highest likelihood of leading to nonconforming products. The assumption in this system is that the problems experienced in the performance of the system are due to deviations from the normal operations of the system. Hence, failure to follow the system requirements leads to nonconforming products (Mannan & Lee, 2005, p.27). The identification of the deviations is useful in preventing the occurrence of hazards. Identification of deviations is aided by the use of guidewords that are systemic of the checklist of the various perspectives of the deviations. The technique uses a bottom-up risk assessment approach in the identification of the deviations that cause the hazards. The following terms are useful in Hazard and operational analysis and help in identification of the deviations (Raman & Cameron, 2005. P. 155). Hazard: The source of the harm resulting from operation deviations Harm, which causes injury from hazards Risk: Is the combination of the results of harm and the extent in which the harm can be severe. There is a need for the engineering company to adopt this analysis technique since it is useful in assessing the designs that are in accordance with the system specifications. It is also beneficial in the identification of the weaknesses in the company. The hazards and operational analysis are able to detect hazards that are not easily notices and isolated from the system. Therefore, adopting the hazard and operational analysis will help the organization to identify the deviations (Raman & Cameron, 2005. P. 158). Energy Trace Barrier Analysis This is an energy source related system, which is used to detect hazards that are associated with hazardous sources of energy. This system aims at tracing the flow of hazardous energy from their sources to workers hence creation the barrier that will prevent the flow of energy. The system also focuses on the various changes of energy forms in a system. This detection technique is used to detect extremely hazardous energy from a well know system, which is complex such as the acquisition of new nuclear instruments. The process involves identifying the energy present is a system and locating the source of energy. After proper location of the energy sources is identified, the flow of energy is determined in order to establish the best barrier or mechanism of confining the energy (Stephans, 2012, Pp. 144-149). Adoption of proper mechanisms is necessary in order to prevent escape of energy by establishing the risk that arises from the hazard. Finally, the best control mechanism is developed and implemented to improve the safety of the workers in the organization. There is the need for the company to adopt this analysis procedure since the methodology detects hazardous energy of all types. The method also ensures an efficient protocol for the identification of hazardous energy in the systems. The method is applicable for use in existing systems and new systems. In addition, this method is easy to use hence can be applied any system (Stephans, 2012, P. 150). Human Error Assessment and Reduction Technique This technique is dependent on the human reliability in performing a particular assigned task. In this technique, the probability of a human error occurring during the completion of a task is evaluated and analyzed. After the evaluation, the appropriate measures are taken in order to reduce the occurrence of the human errors in the systems (Mannan & Lee, 2005, p.20). Human errors in most cases lad to failures of some systems hence lead to a catastrophic accident in many engineering organizations. The human error assessment and reduction technique identifies all human error, quantification of the error identified and reduction of the error. In the process of performing a task, there is a probability that an error may result from human beings performing the task. Human errors result from different causes such as tiredness, ignorance, and distraction (Redmill & Anderson, 2007, p.205). The steps in human error assessment and reduction technique are as follows. Identifying the task an operator requires in completing a certain task The task is described fully, and a human unreliability score is established for the task The final human error probability is calculated The organization should adopt this technique, as it will reduce the errors that are likely to result from human beings. Errors in a vital task may lead to failure of the organization to achieve its objectives. The technique is also easy to use since it provides the user with several suggestions on how to minimize the errors in the given task (Sandom & Harvey, 2004, p. 151). Technique for Human Error Prediction This human reliability technique predicts the human error. In this technique, human errors are assumed that the probabilities of different performance factors such as working time, temperature, and complexity of the assigned task. This involves the likelihood of detecting the error, recovery probability, and effects of the error if not corrected. The human errors are broken down into omission errors and commission errors (Redmill & Anderson, 2007, p.203). During the process of analysis using a technique for human error prediction, the task to be performed is decomposed into various elements. The human operations involved in the task are listed in order to identify the possible errors that may occur to suggest the best recovery modes. The next step involves assigning nominal human error predictions ton each element in order to determine the prediction shaping factors for each element. The effects of dependence among tasks are calculated, and quantification of all total human errors (Redmill & Anderson, 2007, p.205). The technique is vital in the analysis of designs, as it allows for the comparison between different systems. The techniques is also useful in selection of the work force to use in the organization since it helps in determining the type and level of the work force, and in predicting the effectiveness of a system in completing a task in order to assess whether the requirement were met. In addition, the technique for human error prediction is useful in determining the requirements for training and development (Redmill & Anderson, 2007, p.207). References Mannan, S., Lee, F. 2005. Lee's Loss Prevention in the Process Industries: Hazard Identification, Assessment, and Control. Oxford: Butterworth-Heinemann. Raman, R., Cameron, I. 2005. Process Systems Risk Management. London: Academic Press Redmill, F., Anderson, T. 2007. The Safety of Systems. London: Springer Sandom, C., Harvey, R. 2004. Human Factors for Engineers. London: IET Stephans, R. 2012. System Safety for the 21st Century: The Updated and Revised Edition of System Safety 2000. New York: John Wiley & Sons. Read More