Risk and Safety Engineering - Assignment Example

Running Head: Risk and Safety Engineering Name: Instructor: Date: Task 1: Hazard and Operability (HAZOP) Introduction Safety management system has safety risk management has one of its functions. One of the key components that make up safety risk management is the identification of risks. This paper seeks to identify and define risk safety events and undesirable outcome in the context of the example of a steering well system. It also tries to find out the risk controls taken to avoid the possible consequences of the events. Further more, I also recognize the fact that a steering system is a complex system that has comprises the interaction of the human-centered systems and the technical parts. Several tools have been and techniques of hazards identification have been found out with their advantages and disadvantages noted. This paper however focuses on one of this technique that is the Hazard and Operability Studies (HAZOPS) Hazard and Operability (HAZOP) Study HAZOP is a structured approach that is systematic and uses both the deviation guidewords and parameter. The technique relies mostly on a well detailed system that describes the system and is readily available for study. The system is broken down into sub systems that have process flows between these subsystems. The elements of the system are further sub-divided and subjected to discussion by experts of multidisciplinary group. Some of the advantages and disadvantages of the system include but not limited to the following. Advantages Rigorous and systematic Applies in a range of types of systems Comprises interaction of varied views from multidisciplinary experts Has a detailed record of hazards identification process that is auditable Disadvantages Takes time to prepare Relies mostly on the its chairman skills Expensive since its time consuming Inhibits imaginative thinking for other types of hazards Specific Tools and Techniques for Hazards Identification These are the tools and techniques of hazards identification. Any system is remembered to have people, procedures, equipment and an environment in which the operations take place. All the elements have to be considered during hazards identification taking into consideration the specific techniques that this type of the system has. For the case of a steering wheel system is can be found out that this is a functional type of a system Safety events Safety barriers Undesirable event Mitigations Potential outcomes Consequences Improper handling of the steering wheel Handling of the steering wheel training Driver mishandle the steering wheel Steering wheel fixings Toppling of the vehicle Aborted steering control Poor quality of material used in making the steering system Drivedrome manual Steering system signage Losing of control by the vehicle Multiple fatalities Inadequate maintenance of the system Driver reporting scheme Steering system /stop bars Vehicle incursion Vehicle stopping delay ATC reporting scheme Steering system maintain ace Loss of location and direction awareness vehicle/ground movement uncontrolled Improper vehicle trim configuration Driver training Simulator training on aborting a taking a stop-off Aborted take-off Movement uncontrolled Task 2: Fault Tree Analysis Steps in Carrying out a Fault Tree Analysis in a partial qualitative tree The following are the steps or events/ steps that need to be followed and mentioned while coming up with a fault tree in the above mentioned system in order to be deemed successful. Identification of the objective for the FTA for the steering system Definition of the top event of the FT in the steering system Definition of the scope of the FTA in the system Definition of the resolution of the FTA for this steering system Definition of the ground rules for the FTA in the system Construction of the FT. Evaluation of the FT. Interpretation and presentation the results. Problem formulation makes the first 5 steps or events that form the partial qualitative fault tree while the remaining 10 form the construction part of the fault tree which involves evaluation part of the tree diagram and the results and interpretation of the results part. Most of these steps in the tree diagram are performed sequentially while other like the third, fourth and fifth ones can be performed concurrently. There is also the modification of the fourth and fifth in the sixth and seventh steps while its relationship with the 8 steps shown in the diagram below The feedback is indicated in the figure. Partial qualitative tree Define FT Top Event Feedback Evaluate FT Construct FT Fault Tree Analysis Steps. The key thing that will ensure the success of the fault tree is having a clear objective spelt out in the FTA. This has been one of the challenge faces by most systems that have been created to come up with the FT that solve a problem that exist in the system. For this case the FT for this system, it aims at coming up with the solution to solve the system failures that exist in the system which is to address he problem of steering wheel failure which has occurred in system. Once there is a clear objective for the fault tree, the top event is derived which in this case is the “loss of control of the steering wheel” which form the main area under the failures of the system revolves around. This can be determined through having their probability determined. The As the time goes by, the effect is defined in this manner after which the previous event of the FT is in. This forms parts of the second step. In the first event of the FT, the failure causes will be resolved and the probability of failure dogged. The most important event will always define the failure style of the system that will be analyzed. Sometimes the main aim is to understand and define more than one failure. In such a scenario, the separate top events are defined. In a given mission, there might be several aims and the resulting burden hierarchy sometimes might be different depending on the fastidious objectives given the priority for the analysis. Incase of a mission having different phases, the independent top event for each phase might need to be defined. In step 3, the variety of the analysis is defined. The range of the FTA determines the failures and the contributors to be included and those to be locked out. The range of the FTA includes the particular design as well as the version and historical time scope related to the system to be analyzed. The scope at last should include the boundary conditions for the analysis. These boundary conditions include the original states of the mechanism and the configuration as well as the boundary. For example the failure of a flight control system is analyzed. In defining the scope, the process of the system to be analyzed is first identified, the mode of operation is also defined, and the component failures to be considered are also indicated. In the 4th step of the process, the declaration of the FTA is well defined. The declaration is the level of detail in which the failure leads to the top event which is developed. If incase the top event is a functional failure of the system, such as crash to operate, then the most top event is normally resolved to the major mechanism in the system. The good examples of major components are the valves, pumps and the pistons. On the other hand, if the main event is the phenomenological failures such as the engine failure due to explosion then the resolution is the intensity of the detail to which the level of explosion will be modeled. The main objective of getting the quantitative model is usually based on the need to have the most possible cause of the explosion considered in the data and any other available conditions. Liability foliage is usually developed to the level of detail where the best failure probability is arrived at. When the decisions about the subcomponents are being made or when an event cannot be shown to be independent of others, then further resolutions are undertaken to reach the solution. Where the risk discrimination no longer matters, the FT is usually developed to a level of detail. This is often a must. In the 5th step, any ground regulations for the FTA are defined. These primary rules include the process and the classification by which actions and gates are named in the FT. These naming schemes are necessary in creating a comprehensible FT. the ground rules are also formulated with the purpose of getting the specific failure model in the FT. the creation of the ground rules in the system are also essential in providing consistency among various FTs especially when different people are developing them. These modeling ground rules may include the method in which precise component failure, human errors and ordinary grounds failures are to be modeled. The 6th step involves the concrete construction of the FT. This subsequent section describe in aspect the thinking and judgment that is involved in constructing the responsibility ranking from the systems schematic and images. The signs that are used in the construction ranking to represent the association between events are also described. Step 7 involves the assessment of the FT. The assessment includes both a quantitative and qualitative assessments. The qualitative assessment provides information on the negligible cut sets for the summit event. The success sets may also be identified that makes sure of the top event. Both the nature of the fundamental events and the number of basic events in the general set gives significant information about the peak incidence. Cut sets are always sorted by cut set order to give out the information about the combination of the basic events that can result in the top event. On the other hand, the quantitative assessment produces not only the chance of the top event but also the leading cut set that can as well contribute to the top event probability. The cut sets in this case are sorted by the probability method and law probability cut sets are shortened from the study. The different quantitative significance is determined for separate applications. The sensitivity studies and the uncertainty evaluations always provide great key information. Finally, step 8 involves the interpretation as well as presentation of the results. The emphasis in this step is placed upon the interpretation and not the presentation only. Many FTs have failed to raise significant impact since the results were simply documented in a report. The results should always be interpreted in order to give tangible implications, especially regarding the potential impact upon the purpose. If the manager is given only asset of mathematical values then the analysis may have a title crash and may likely hinder the managers from discussing the future FTA Task 3: Qualitative Evaluations approach of a Fault Tree There two evaluation approaches that are followed during the FT. These are the qualitative and quantitative evaluation approaches that can be used. FT is however a qualitative assessment in nature which comprises of both events and relationships that all lead to the top event. The construction of FT needs to be done with the bearing in mind of the significant understanding and insights on what the cause of the top event which in this case is this project is the losing of control of the steering wheel. The additional evaluations seek to further refine the information that FT provides. Transformation of FT logic into logically equivalent forms is the basic tasks by the qualitative evaluations providing additional information. Minimal cut sets (MCs) are the main qualitative results from the top event that is the result of the loss of the steering wheel in the case of this specific system. The combination of basic and immediate events cause the steering wheel to loss control with the MCs being the smallest of the basic events that ought t be combined and are obtained from the intermediate events like in the case of the steer by wire system, gates for the FT this system.MCs further give additional information that is important in providing and identifying the single failure casing the top event that is the losing of the control of the steering wheel to occur. Single failures are the weak limits that are the focus of the upgrade and prevention actions. Some of the most useful information is the events that can occur in the FT and obtained through the qualification of the FT. prioritization of the resources is based on the importance of the event to the loss of the control of the steering wheel. All these events are important and should be determined through calculation of the probability of the top event that all the factors that contribute to the failure of the steering wheel. The decrease in the probability of the top even that is the loss of control of the steering wheel is prevented form taking place. This is possible through the execution of several events that include but not limited to the prevention of activities from occurring, upgrading the activities, prioritization and maintenance of the repair activities from the FT created from this system. REFERENCE Read More