Chapter 15 - Failure-Mode Analysis

14 - Failure-Mode Analysis

Analysis of low isolation problem in HMC using Ishikawa model: A case study

Majority of the human resource for the effective working of the engine of growth of a country emanates from the higher education system of a country. But the falling quality of output from the Higher education system in India is presenting a major challenge and concern in front of the policy makers. Falling quality among the Higher education system can be judged by observing various major indicators some of which are, the inefficiency of Higher education system in generating employment opportunities and development of output which is not only poor in hard skills but also lacks soft skills which are essential for the growth and development of the human resource. To deal with this issue it is important to look at the root cause of the problem. The present study focuses on the root cause of such problems which apparently is hidden in the school education system in the country.

Nowadays, development has become a natural part of our lives, the dynamics and types of which are the only things we tend to highlight and compare. This is why it may seem unusual that science has identified an anomaly in certain territorial units where there is a lack of development. This situation has been called the development trap. The development of an area is, of course, dependent on a great many factors, so that the range of development traps seems almost inexhaustible. This paper takes stock of the development traps identified so far, not with the aim of questioning the methods used, but to evaluate the data and indicators used to identify them. The study concludes that macro-level data are not causes but consequences, masking the true root causes of problems, but they play an important role in establishing a diagnosis at the regional level. The study aims to provide a convincing illustration, using concrete examples, of the development policy approach - and its main features - that can help to overcome the various pitfalls.

The paper reports the investigation on the root cause of source-drain leakage in bulk FinFET devices. While the failing device was readily isolated by nanoprobing technique and the electrical analysis pinpointed the potential defect location inside the Fin channel, the identification of physical root cause went through extreme challenges imposed by the tiny-sized device and the unique FinFET 3D architecture. The initial TEM analysis was misled by the projection of a species in the lamella surface and thus could not explain the electrical data. Careful analysis on the device structure was able to identify the origin of the species and led to the discovery of the actual root cause. This paper will provide the analysis details leading to the findings, and highlight the role of electrical understanding in not only providing guidance for physical analysis but also revealing the true root cause of failure in FinFET devices.

This study aims at developing an analysis method for failure mode relating to material properties by considering simulated design specifications of a functional model. The proposed method contains the following procedures: (1) developing a simulated design specification of a functional model, (2) performing failure mode analyses by inserting deviation patterns into the design specifications and (3) identifying failure modes and root cause analysis to identify failure causes relating to material properties. The proposed procedure was applied in a pilot study using a simplified laser irradiation machine. The group who used the proposed model, which is based on design review based on failure modes, showed a higher rate of success in people detecting material-relating causes, compared with the group who used conventional failure mode and effect analysis. Therefore, the proposed model effectively supports users to identify causes of failure modes regarding material properties for functional materials.

Background: Patient safety is the first step to improve the quality of care. Objectives: Therefore, the present study aimed to examine the risk assessment of processes in a pediatric surgery department using the Health Failure Mode and Effect Analysis (HFMEA) in 2017 - 2018. Methods: In this research, a mixed-method design (qualitative action and quantitative descriptive cross-sectional study) was used to analyze failure mode and their effects. The nursing errors in the clinical management model were used to classify failure modes, and the theory of inventive problem solving was used to determine a solution for improvement. Results: According to the five procedures selected by the voting method and their rating, 25 processes, 48 sub-processes, and 218 failure modes were identified with HEMEA. Eight risk modes (3.6%) were found as non-acceptable risks and were transferred to the decision tree. The main root causes (hazard score ≥ 4) were as follows: Technical-related factors (14.34%), organizational-related factors (31.9%), human-related factors (45.3%), and other factors (7.6%). Conclusions: The HFMEA method is very effective in identifying the possible failure of treatment procedures, determining the cause of each failure mode, and proposing improvement strategies.

Aggregated results from twenty years of community-engaged assiduous restoration of severely degraded coastal littoral systems in New Zealand (NZ) reveal numerous fundamental and substantive natural improvements to dune form, function, and storm resilience. This is accomplished by simple, low-cost exclusive utilisation of the variably threatened local indigenous dune plant species. These valuable and innovative enhancements succeed countless decades of cascading consequences from numerous impacts instigated by historic (and frequently continuing) damaging effects on those previously natural coastal dune ecosystems – impacts that subsequently induced problematic littoral retreat – the true root cause of prevailing coastal erosion. The durable reversals were often generated in less than two decades, contemporaneously with adverse storm surge and sea level rise conditions. Research reveals many global dune ecosystems are afflicted with analogous normalised degradation and erosion difficulties, with the earliest active circumvention recorded in sixteenth century Denmark (McKelvey 1999). Historic plus current pressures such as coastal settlement impacts and continuing agricultural use of dunelands similarly threaten numerous global littoral margins, alongside recent concerns regarding the compounding effects of climate change. Successful, affordable, diligent dune restoration work pioneered in NZ has extensive benefits for other nations experiencing similarly challenging attrition on degraded coastal zones. Persuasive data is presented to validate the numerous persistently accrued benefits of this cost-effective and enduring coastal adaptation response.

29 - Determine Causes of Variation

Iron sulfide scale is found almost ubiquitously in maturing oilfield produced water handling and injection systems. Keeping injection systems clean of sulfide scale is becoming more of a shared challenge, but there are few examples where true root cause analysis has led to specific laboratory testing and development of bespoke removal and prevention methods. This paper aims to link these aspects by sharing the best practices from around the world with cutting edge techniques and chemistries used to maintain flow assurance and injectivity in produced water handling systems affected by iron sulfide scale. Discussion includes root causes analysis of iron sulfide scale formation and deposition mechanisms focusing on the interplay of pH, along with sources of iron and sulfide. The paper goes onto discuss laboratory and field evaluation of control methods. Finally, the root causes of iron sulfide scale formation and deposition mechanism, including the relative advantages and merits of the different techniques, including: Chelating agents (for iron sequestration) Surfactants (for water wetting) Biocide (to target SRB and biofilm) Corrosion inhibitor (to lower iron in system) Sulfide scale inhibitors (threshold inhibition of scale) Additionally, case histories are used to elaborate the theoretical discussion. The first case history is from an offshore oilfield water injection system, where fouling occurred due to changes in the flow assurance strategy further upstream and capture the lessons learned on the interplay of different production chemicals. The second case history concerns an onshore oilfield with a vast water injection system of over 3,000 wells supporting approximately 5,000 production wells. The paper concludes with a summary of the decades of experience of solving the most challenging sulfide scaling scenarios, as well as cutting-edge research on a new class of polymeric exotic sulfide scale inhibitor dispersant, effective as threshold concentrations against even lead and zinc sulfide.

Modern large frame F, G, & J class gas turbine flow path component design requires the complex integration of multiple design disciplines that traditionally reside with distinct specialists. A traditional design system for an actively cooled gas turbine blade includes aerodynamicists, heat transfer engineers, structural engineers and a failure or lifetime prediction engineers passing information through a manual process with a small number of iterations between the disciplines. Design or manufacturing engineers can also be involved ensuring manufacturability and policing best practices in a predominantly deterministic design system. Over the past few decades robust design or probabilistic design philosophies along with cluster computing advancements have accelerated the release of commercial software that allows for the automation of multiple analytical evaluations at off design points. These software codes allow for process automation of several independent codes executed multiple times at various conditions for automated design of experiment (DOE), and reliability analysis using Monte Carlo or other advanced approximate probabilistic methods across the entire design system. In this paper, the authors are presenting a novel approach of using a commercially available process integration tool to fully integrate a series of other commercially available tools for a root cause failure analysis of a F class turbine blade rather than a new make design. The analysis incorporated a computational fluid dynamics model (CFD) to define inlet temperatures and pressure profiles, a fully conjugate thermal analysis interacting with a finite element (FEA) solver linked to a proprietary creep lifetime prediction model. A DOE was executed to define the meaningful parameters and help rule out potential causes of failure such as loss of coating or compromised cooling system as a contributing factor of the failure which greatly reduced the amount of time and money needed for the investigation. A probabilistic failure analysis was then executed and surrogate models created for quick probabilistic assessment for different operating conditions. This allowed for validation against fleet history to explain the single engine failure not previously observed. Setting up the non-deterministic models initially allowed for rapid redesign in less than 1 month time with confidence that the true root cause was identified and mitigated. It further allowed for feedback and calibrations to the traditional design system methodology.

Historically, the most common failure analyses metrologies have been dye-and-pull, cross-sections, microscopy, optical and SEM. Using these traditional metrologies to find a root cause from a dynamic event can be very time consuming and sometimes inconclusive. The standard methodology is to work backward to reconstruct the “event” that caused or initiated failure. Often times the root cause is not immediately obvious and design improvements require an iterative process to identify the true root cause. This approach is costly in time, materials and resources. A high speed camera (HSC) allows identification of failure from a point of initiation. Using the point of initiation concept with reconstructive modeling allows a design team to discover potential initiating sources and better match a cause to the effect and implement corrective action. This decreases development time, minimizing product design cycle and increases market opportunities.

An Indonesia manufacturing company producing Airbus wing parts experienced losses of more than $100,000 in 2017. The production of A 380 wing parts contributed to 73% of the total losses, and 37% came from parts production of A 350 and A 320. The study focused on the most significant contribution losses of A 380 wing parts that is Drive Rib 1. This paper aims at examining the root cause of the loss in A 380-Program, solving the root cause by proposing the alternative solution, and improving the performance in A 380 Program. By conducting the interview and archival data, the data were analyzed employing Root Cause Analysis (RCA) to discover the root cause of problems. Low reliability of the production machine (DGAL Cincinnati Milacron) was identified as a root cause indicated by Overall Equipment Effectiveness (OEE) at 50.3% used since the 1980s. According to Total Productive Maintenance (TPM), this study proposes three alternative business solutions (autonomous maintenance, quality maintenance, and machine replacement). By considering the results of OEE and Analytical Hierarchy Process (AHP) with three criteria (cost, benefit, and implementation), the problem-solution proposes two approaches, namely conducting the autonomous maintenance with an improvement of OEE about 7% for the short term period and organizing the machine replacement with a significant OEE improvement about 17.1%.

For the reliability of micro inertial measurement unit (MIMU), the failure mode analysis and random vibration test are carried out. Firstly, based on the structure and function analysis of MIMU, the MIMU failure mode, effects and criticality analysis (FMECA) which is carried out to obtain the key failure modes, reliability critical parts and weak parts of MIMU. Secondly, The MIMU vibration step test with a wide-band (15Ηz-2ΚHz) is designed and carried out. It can be concluded that when the environmental stress is overloaded, the MIMU will have sudden failures such as information calculation errors. Under normal stress, gyroscope performance degradation and accelerometer performance degradation are the main failure modes of MIMU. The research can provide reference for MIMU reliability design and evaluation.

The exploration of traffic areas as a novel photovoltaic integration opportunity within the traffic sector, specifically in road surfaces, has been demonstrated in various projects. Limited data and publications about the performance and failure modes of these innovative road-integrated modules highlights the need for a comprehensive failure analysis. This study focuses on first time assessing failure modes of road-integrated photovoltaic modules installed at Austria's first road-integrated PV system in Teesdorf. A comprehensive failure mode analysis is conducted at the 100 m2 PV parking place using a combination of quantitative and qualitative methods. These methods include regular visual inspections, I-V-curve measurements at both string- and module-levels (with a simplified STC correction), electroluminescence- and dark-I-V-curve measurements, and the use of monitoring data. The PV parking place produced 10.2 MWh in its first operation year, 27.18% less than the estimated yield. Visual inspections reveal various failure modes, including detachment of the module top layer, delamination, and broken module edges. In the analysed monitoring data continuous power losses are observed over the systems operation time. String-level power losses of up to 47.8% (mean: 33.5%) are calculated for the first year of operation. For the second year of operation the power losses reach a up to of 77.5% (mean: 56.2%). Cell cracks as the main cause of these power losses, attributed to vehicle loads, are identified through electroluminescence images. Out of 16 analysed strings with dark I-V-curve measurements three showed at least one bypass diode malfunctions. The combination of quantitative and qualitative methods identified multiple failure modes and their main causes. As a conclusion, the study highlights the challenges of integrating PV modules into road surfaces, emphasizing the need for standardisation and quality assurance in the field of road-integrated PV applications.