Fault Tree Analysis

2016 ◽  
Vol 32 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Lisa M. McElroy ◽  
Rebeca Khorzad ◽  
Theresa A. Rowe ◽  
Zachary A. Abecassis ◽  
Daniel W. Apley ◽  
...  

The purpose of this study was to use fault tree analysis to evaluate the adequacy of quality reporting programs in identifying root causes of postoperative bloodstream infection (BSI). A systematic review of the literature was used to construct a fault tree to evaluate 3 postoperative BSI reporting programs: National Surgical Quality Improvement Program (NSQIP), Centers for Medicare and Medicaid Services (CMS), and The Joint Commission (JC). The literature review revealed 699 eligible publications, 90 of which were used to create the fault tree containing 105 faults. A total of 14 identified faults are currently mandated for reporting to NSQIP, 5 to CMS, and 3 to JC; 2 or more programs require 4 identified faults. The fault tree identifies numerous contributing faults to postoperative BSI and reveals substantial variation in the requirements and ability of national quality data reporting programs to capture these potential faults. Efforts to prevent postoperative BSI require more comprehensive data collection to identify the root causes and develop high-reliability improvement strategies.

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 133
Author(s):  
Feel-Soon Kang ◽  
Sung-Geun Song

An improved hybrid submodule employs a direct current (DC) short current protection function to improve the reliability of a high-voltage direct current (HVDC) system. However, it increases the number of circuit components to implement the protection. So, we need to evaluate the relationship between the protection function and the increased number of circuit components to assess whether the improved hybrid submodule (IHSM) is suitable to practical application or not from the viewpoint of reliability. Although conventional part count failure analysis considers the type and the number of parts, it cannot reflect the operational characteristics of the submodule. To overcome this problem, we design a fault tree that reflects the operational characteristics of IHSM and calculates the failure rate by using MIL-HDBK-217F. By part count failure analysis (PCA) and fault-tree analysis (FTA), we prove the high reliability of IHSM compared to half-bridge, full-bridge, and clamped-double submodules.


2012 ◽  
Vol 588-589 ◽  
pp. 1718-1722
Author(s):  
Jia Chun Wang ◽  
Jin Xiu Zhang ◽  
Qing Fa Liu ◽  
Chong Min Jiang

The rotary working table of C5250 vertical lathe requires high reliability. Based on the Fault Mode and Effect Analysis, the fault-tree of “guide surface lapping damage about rotary table” was established. To solve the problem of failure probability of bottom events obtaining insufficiently, fuzzy set theory was introduced into the fault tree analysis method. The failure probability distribution of bottom events was described as triangular fuzzy number. The occurrence probability distribution of the top event and the fuzzy importance of basic events were calculated according to fuzzy calculation rule. Through the analysis, the weak reliability links of the fault tree such as hydraulic pump, oil film thickness measuring installation and hydraulic valve were found out.


Author(s):  
Kamal Hamid ◽  
Nadim Chahine

Wireless communications became one of the most widespread means for transferring information. Speed and reliability in transferring the piece of information are considered one of the most important requirements in communication systems in general. Moreover, Quality and reliability in any system are considered the most important criterion of the efficiency of this system in doing the task it is designed to do and its ability for satisfactory performance for a certain period of time, Therefore, we need fault tree analysis in these systems in order to determine how to detect an error or defect when happening in communication system and what are the possibilities that make this error happens. This research deals with studying TETRA system components, studying the physical layer in theory and practice, as well as studying fault tree analysis in this system, and later benefit from this study in proposing improvements to the structure of the system, which led to improve gain in Link Budget. A simulation and test have been done using MATLAB, where simulation results have shown that the built fault tree is able to detect the system’s work by 82.4%.


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