(a) Complete the conversion of this cause tree into a FAULT tree, allowing for testing the alarm system once per week. (Use the simple fractional dead time formula.)
(b) State which pieces of equipment have the greatest effect on the top event frequency.
(c) If the reliability of the level detector and controller can be improved from a fault frequency of 2.36 and 1.64 respectively to 0.5 per year, determine the new top event frequency
Fault tree analysis mainly defined as the deductive and top-down evaluation of failure which tends to results to a system with the makeable undesired state. The evaluation mainly grounded on the Boolean logic which combines the lower-level events series.
This analysis mainly incorporates the application of the reliability as well as safety engineering with the aim of ensuring that one understands the occurrences of the failures in the system decisively. For this evaluation the occurrence of the overall norm mainly illustrated as indicated in the analysis below.
State which pieces of equipment have the greatest effect on the top event frequency.
From the observation that some amount of hydrogen gas is enclosed somewhere in the chambers closer to the regions that Welder had initiated his work, it can be inferred that an explosion if fire may erupt. Consequently, a possibility that the worker alongside his gear might also be on fire is also noted. From this understanding, there must be some emergency measures put in place to prevent further damages. These include alarms, a swift and immediate use of fire extinguishers, making the sections free from anything and making available an ambulance or medical van to the victims. All measures should be taken into account in order to bridge any gap and negligence from the maintenance personnel (Yuan, Cui, Tao, & Ma, 2018).
of workers while at the work area. Lastly the concern of do’s and don’ts while on the site should be carefully taken care of in the long run.
If the reliability of the level detector and controller can be improved from a fault frequency of 2.36 and 1.64 respectively to 0.5 per year, determine the new top event frequency.
Quantitative analysis in line with the fault tree illustration provides one with the viable opportunity on how to determine the emerging critical events in regard to the top event. The analysis also stipulates that the resultant norm must be beneficial in the long run. In essence, it helps in determining the probability as well as frequencies in line with the Prime events and occurrences in the long run. there are two main methods used in the determination of the quantitative in the analysis. The two methods are the cut sets and the working up tree. Preferably, each procedure tends to have both the disadvantages and the advantages in line with the individual analysis (Munk et al. 2018, June). The first method mainly applies in the computation of the individual gate turns. The analysis mainly grounded on aspects such as the no power charger or low probabilities. Thus, the analysis operates on the principles of the instantaneous probabilities of the makeable faulty transformer of item 4. However the items used in the process should be independent . the evaluations has to be repeated often until the viable value is gathered as the Top event in the long run.
On the other hand, the second method encompasses on the identification of all the cut sets in ensuring that the lead TOP event is obtained in the run. The evaluation mainly carried out for each of the event and the summation of the results documented in the long run. The method has the advantages in that it leads to the obtaining of the dependent failures. Conversely, it is important to note that considerations should be incorporated since the summation of the independencies often obtained prior (Mhenni, Nguyen, & Choley, 2018).
Frequencies are 2.36, 1.64, and 0.5
Also, probability for the OR-gate and the AND-gate mainly given with the below expressions (Jankovsky, Denman, & Aldemir, 2018).
Thus, the power supply failure mainly expressed in line with the below analysis (Bethea, 2018).
The reliability computation mainly illustrated as follows (Wang, Chen, Wang, & Ye, 2018).
Probability for the top event given as
(A+B). [C.E + D.E + C.C + D.C + D.E)
OR-gate A= (0.6+0.04+2.36) = 3
OR-gate B=(0.97 x 0.03) = 0.029
(A.B) = (3 x 0.029) = 0.0873
OR-gate C= [1.64 + 0.05 + 0.07+0.6]
The combination of the OR gate and the AND-gate at
= [0.0873 x 2.36]
The new event is given as
In summary, the paper discussed the hazard analysis in the mechanical engineering via the application of the Fault tree analysis and Boolean logic system. The analysis also incorporated the calculation of the probability and the top event in line with OR-gate and AND-gate.
Bethea, R. M. (2018). Statistical methods for engineers and scientists. Routledge.
Jankovsky, Z. K., Denman, M. R., & Aldemir, T. (2018). Dynamic event tree analysis with the SAS4A/SASSYS-1 safety analysis code. Annals of Nuclear Energy, 115, 55-72.
Mhenni, F., Nguyen, N., & Choley, J. Y. (2018). SafeSysE: A safety analysis integration in systems engineering approach. IEEE Systems Journal, 12(1), 161-172.
Munk, P., Abele, A., Thaden, E., Nordmann, A., Amarnath, R., Schweizer, M., & Burton, S. (2018, June). Semi-automatic safety analysis and optimization. In 2018 55th ACM/ESDA/IEEE Design Automation Conference (DAC) (pp. 1-6). IEEE.
Wang, T., Chen, J., Wang, C., & Ye, X. (2018). Understand e-bicyclist safety in China: Crash severity modeling using a generalized ordered logit model. Advances in Mechanical Engineering, 10(6), 1687814018781625.
Yuan, C., Cui, H., Tao, B., & Ma, S. (2018). Cause factors in emergency process of fire accident for oil–gas storage and transportation based on fault tree analysis and modified Bayesian network model. Energy & Environment, 0958305X18760222.