Accelerated Reliability Growth Testing and Data Analysis Method

2007 ◽  
Vol 50 (2) ◽  
pp. 98-117 ◽  
Author(s):  
Milena Krasich
Keyword(s):  
Data Analysis ◽  
Failure Modes ◽  
High Reliability ◽  
Real Life ◽  
Accelerated Life Test ◽  
Analytical Models ◽  
International Electrotechnical Commission ◽  
Reliability Growth ◽  
Time To Failure ◽  
Growth Test

Traditionally, a reliability growth test was performed at the levels of various operational and environmental stresses, often at a level equal to that expected in use. Other than formal failure modes and effects analysis, reliability growth tests were often the only practical means for identification and mitigation of failure modes of a newly designed product. With the present high reliability requirements and long product useful life, the length of reliability growth tests may become cost and schedule prohibitive; therefore, accelerated testing is taking the place of prior testing at the use levels. This practice, however, does not address the dilemma of possibly unrealistically skewed test results highly dependent on the sequence of individually applied stresses as, unfortunately, it is often difficult to impossible to apply all of the environmental and operational stresses simultaneously. An example of this problem would be a case where the majority of failure modes in a product are a result of or are related to a specific stress, and this test was performed early in the program. These early failures would then produce a high growth rate and an incorrect estimate of the product achieved reliability if the analysis were done by standard analytical models. The test data also may be skewed in the opposite way, producing little or no reliability growth. This concern has been addressed as a serious caution in Edition 2 of the International Electrotechnical Commission (IEC) 61014 Programmes for reliability growth. This study shows how data analysis applied to an accelerated life test based on reliability growth methodology may produce a viable solution to the calculation problems. The stresses applied in this test are an accelerated application of most of the stresses expected to take place during product use. Each of the tests represents a lifetime exposure to an individual stress. If those stresses are applied individually and in sequence, they are considered to be equivalent to being applied in parallel with one another, as the duration of each stress is calculated to represent life of the product. Time to failure in each test is re-calculated to represent time to failure in real life. Failure occurrences are then sorted in their increasing order and analyzed using one of the reliability growth test analytical methods.

Reliability Assessment Based on Performance Parameter for Micro-Gyro

2014 ◽  
Vol 1037 ◽  
pp. 197-200
Author(s):  
Li Xia Yu ◽  
Li Qin ◽  
Meng Mei Wang
Keyword(s):  
High Reliability ◽  
Reliability Assessment ◽  
Assessment Method ◽  
Accelerated Life Test ◽  
Time To Failure ◽  
Accelerated Life ◽  
Parameter Measuring ◽  
Failure Life ◽  
Effective Assessment ◽  
Short Time

For high-reliability and long-lifetime product, it is difficult to assess the reliability with traditional accelerated life test that record only time to failure. Aiming to solve the problem of the previously, a reliability test and assessment method forecasting the life of samples based on degradation parameter was proposed. According to the working characteristic, the key parameter measuring performance degradation was selected. Based on statistical analysis methods, parameter degradation was designed and parameter degradation model was build. Combined with practical application background, the failure threshold was set and reliability assessment resultwas obtained. The method is applied to assessing reliability of micro gyroscope. The application shows that the method can achieve effective assessment, which can be used as similar products that are difficult to obtain the failure life data in a short time.

scholarly journals A Matrix FMEA Analysis of Variable Delivery Vane Pumps

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1741
Author(s):  
Joanna Fabis-Domagala ◽  
Mariusz Domagala ◽  
Hassan Momeni
Keyword(s):  
Risk Analysis ◽  
Failure Modes ◽  
High Reliability ◽  
Matrix Analysis ◽  
Hydraulic Systems ◽  
Vane Pump ◽  
End Effects ◽  
Root Cause ◽  
Preventative Measures ◽  
Fmea Analysis

Hydraulic systems are widely used in the aeronautic, machinery, and energy industries. The functions that these systems perform require high reliability, which can be achieved by examining the causes of possible defects and failures and by taking appropriate preventative measures. One of the most popular methods used to achieve this goal is FMEA (Failure Modes and Effects Analysis), the foundations of which were developed and implemented in the early 1950s. It was systematized in the following years and practically implemented. It has also been standardized and implemented as one of the methods of the International Organization for Standardization (ISO) 9000 series standards on quality assurance and management. Apart from wide application, FMEA has a number of weaknesses, which undoubtedly include risk analysis based on the RPN (Risk Priority Number), which is evaluated as a product of severity, occurrence, and detection. In recent years, the risk analysis has been very often replaced by fuzzy logic. This study proposes the use of matrix analysis and statistical methods for performing simplified RCA (Root Cause Analysis) and for classification potential failures for a variable delivery vane pump. The presented methodology is an extension of matrix FMEA and allows for prioritizing potential failures and their causes in relation to functions performed by pump components, the end effects, and the defined symptoms of failure of the vane pump.

scholarly journals Perception of social media behaviour among medical students, residents and medical specialists

2021 ◽  
Author(s):  
Sebastiaan A. Pronk ◽  
Simone L. Gorter ◽  
Scheltus J. van Luijk ◽  
Pieter C. Barnhoorn ◽  
Beer Binkhorst ◽  
...  
Keyword(s):  
Social Media ◽  
Data Analysis ◽  
Medical Students ◽  
Online Survey ◽  
Media Use ◽  
Demographic Data ◽  
Real Life ◽  
Clinical Work ◽  
Social Media Use ◽  
Medical Specialists

Abstract Introduction Behaviour is visible in real-life events, but also on social media. While some national medical organizations have published social media guidelines, the number of studies on professional social media use in medical education is limited. This study aims to explore social media use among medical students, residents and medical specialists. Methods An anonymous, online survey was sent to 3844 medical students at two Dutch medical schools, 828 residents and 426 medical specialists. Quantitative, descriptive data analysis regarding demographic data, yes/no questions and Likert scale questions were performed using SPSS. Qualitative data analysis was performed iteratively, independently by two researchers applying the principles of constant comparison, open and axial coding until consensus was reached. Results Overall response rate was 24.8%. Facebook was most popular among medical students and residents; LinkedIn was most popular among medical specialists. Personal pictures and/or information about themselves on social media that were perceived as unprofessional were reported by 31.3% of students, 19.7% of residents and 4.1% of medical specialists. Information and pictures related to alcohol abuse, partying, clinical work or of a sexually suggestive character were considered inappropriate. Addressing colleagues about their unprofessional posts was perceived to be mainly dependent on the nature and hierarchy of the interprofessional relation. Discussion There is a widespread perception that the presence of unprofessional information on social media among the participants and their colleagues is a common occurrence. Medical educators should create awareness of the risks of unprofessional (online) behaviour among healthcare professionals, as well as the necessity and ways of addressing colleagues in case of such lapses.

Optimization of Tube Hydroforming Process Using Probabilistic Constraints on Failure Modes

2011 ◽  
Vol 62 ◽  
pp. 21-35 ◽  
Author(s):  
Anis Ben Abdessalem ◽  
A. El Hami
Keyword(s):  
Failure Modes ◽  
High Reliability ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Forming Limit Diagram ◽  
Plastic Instability ◽  
Probabilistic Constraints ◽  
Forming Limit ◽  
Reliability Based Design ◽  
Hydroforming Process

In metal forming processes, different parameters (Material constants, geometric dimensions, loads …) exhibits unavoidable scatter that lead the process unreliable and unstable. In this paper, we interest particularly in tube hydroforming process (THP). This process consists to apply an inner pressure combined to an axial displacement to manufacture the part. During the manufacturing phase, inappropriate choice of the loading paths can lead to failure. Deterministic approaches are unable to optimize the process with taking into account to the uncertainty. In this work, we introduce the Reliability-Based Design Optimization (RBDO) to optimize the process under probabilistic considerations to ensure a high reliability level and stability during the manufacturing phase and avoid the occurrence of such plastic instability. Taking account of the uncertainty offer to the process a high stability associated with a low probability of failure. The definition of the objective function and the probabilistic constraints takes advantages from the Forming Limit Diagram (FLD) and the Forming Limit Stress Diagram (FLSD) used as a failure criterion to detect the occurrence of wrinkling, severe thinning, and necking. A THP is then introduced as an example to illustrate the proposed approach. The results show the robustness and efficiency of RBDO to improve thickness distribution and minimize the risk of potential failure modes.

scholarly journals A Novel Concept Acquisition Approach Based on Formal Contexts

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ting Qian ◽  
Ling Wei
Keyword(s):  
Data Analysis ◽  
Formal Concept Analysis ◽  
Real Life ◽  
Experimental Results ◽  
New Method ◽  
Concept Acquisition ◽  
Formal Concept ◽  
Knowledge Processing ◽  
Formal Concepts ◽  
Novel Concept

As an important tool for data analysis and knowledge processing, formal concept analysis (FCA) has been applied to many fields. In this paper, we introduce a new method to find all formal concepts based on formal contexts. The amount of intents calculation is reduced by the method. And the corresponding algorithm of our approach is proposed. The main theorems and the corresponding algorithm are examined by examples, respectively. At last, several real-life databases are analyzed to demonstrate the application of the proposed approach. Experimental results show that the proposed approach is simple and effective.

CHANGING THE PARAMETERS OF SOCIAL REALITY UNDER THE INFLUENCE OF A GLOBAL FACTOR

2021 ◽  
Vol 74 (2) ◽  
pp. 56-60
Author(s):  
Zh.A. Kabayeva ◽  
Keyword(s):  
Data Analysis ◽  
Comparative Studies ◽  
Statistical Approach ◽  
Real Life ◽  
Social Reality ◽  
External Factors ◽  
Economic Situation ◽  
The Real ◽  
Global Factor ◽  
Public Consciousness

The aim of the article is to show how external factors influence social reality, what changes are taking place in public consciousness. One of the big factors was the COVID-19 pandemic and its attendant consequences. Complex, intricate dramatic processes are taking place that directly affect the real life of both people and communities and states. These changes, first of all, influenced the economic situation and hence, in general, the very social reality. The work uses the methods of comparative studies, phenomenology, hermeneutics. and a statistical approach to data analysis.

scholarly journals Comparison of TIMS-PASEF quantitative proteomics data-analysis workflows using FragPipe, DIA-NN, and Spectronaut from a user's perspective

2021 ◽  
Author(s):  
Alejandro Fernandez-Vega ◽  
Federica Farabegoli ◽  
Maria Mercedes Alonso-Martinez ◽  
Ignacio Ortea
Keyword(s):  
Data Analysis ◽  
Quantitative Proteomics ◽  
Real Life ◽  
Analysis Tool ◽  
Proteomics Data ◽  
Mass Spectrometers ◽  
Data Independent Acquisition ◽  
Proteomics Experiment ◽  
Under Sampling ◽  
The One

Data-independent acquisition (DIA) methods have gained great popularity in bottom-up quantitative proteomics, as they overcome the irreproducibility and under-sampling limitations of data-dependent acquisition (DDA). diaPASEF, recently developed for the timsTOF Pro mass spectrometers, has brought improvements to DIA, providing additional ion separation (in the ion mobility dimension) and increasing sensitivity. Several studies have benchmarked different workflows for DIA quantitative proteomics, but mostly using instruments from Sciex and Thermo, and therefore, the results are not extrapolable to diaPASEF data. In this work, using a real-life sample set like the one that can be found in any proteomics experiment, we compared the results of analyzing PASEF data with different combinations of library-based and library-free analysis, combining the tools of the FragPipe suite, DIA-NN and including MS1-level LFQ with DDA-PASEF data, and also comparing with the workflows possible in Spectronaut. We verified that library-independent workflows, not so efficient not so long ago, have greatly improved in the recent versions of the software tools, and now perform as well or even better than library-based ones. We report here information so that the user who is going to conduct a relative quantitative proteomics study using a timsTOF Pro mass spectrometer can make an informed decision on how to acquire (diaPASEF for DIA analysis, or DDA-PASEF for MS1-level LFQ) the samples, and what can be expected depending on the data analysis tool used, among the different alternatives offered by the recently optimized tools for TIMS-PASEF data analysis.

scholarly journals Augmented Leadframe Design for Stable Multi-Wire Ground Bonding

2021 ◽  
pp. 1-5
Author(s):  
Frederick Ray I. Gomez ◽  
Alyssa Grace S. Gablan ◽  
Anthony R. Moreno ◽  
Nerie R. Gomez
Keyword(s):  
Failure Modes ◽  
High Reliability ◽  
Semiconductor Industry ◽  
Global Market ◽  
Design Solution ◽  
Package Design ◽  
Strict Compliance ◽  
Bridge Type ◽  
Major Application ◽  
Augmented Design

Technological change has brought the global market into broad industrialization and modernization. One major application in the semiconductor industry demands safety and high reliability with strict compliance requirement. This technical paper focuses on the package design solution of quad-flat no leads (QFN) to mitigate the leadframe bouncing and its consequent effect of lifted wire and/or non-stick on leads (NSOL) defects on multi-wire ground connection. Multi-wire on single lead ground (or simply Gnd) connection plays critical attribute in the test coverage risk assessment. Cases of missing wire and/or NSOL on the multi-wire Gnd connection cannot be detected at test resulting to Bin1 (good) instead of Bin5 (open) failure. To ease the failure modes mechanism, a new design of QFN leadframe package with lead-to-diepad bridge-type connection was conceptualized for device with extended leads and with multiple Gnd wires connection. The augmented design would provide better stability than the existing leadframe configurations during wirebonding. Ultimately, the design would help eliminate potential escapees at test of lifted Gnd wire not detected.

Support Vibration Diagnostics and Limits in Gas Turbines

2016 ◽  
Author(s):  
Marcin Bielecki ◽  
Salvatore Costagliola ◽  
Piotr Gebalski
Keyword(s):  
Gas Turbine ◽  
Test Data ◽  
Gas Turbines ◽  
Failure Modes ◽  
Real Life ◽  
Reliability Function ◽  
Vibration Diagnostics ◽  
Real Life Data ◽  
Industrial Gas Turbines ◽  
Harmful Effects

The paper deliberates vibration limits for non-rotating parts in application to industrial gas turbines. As a rule such limits follow ISO 10816-4 or API616, although in field operation it is not well known relationship between these limits and failure modes. In many situations, the reliability function is not well-defined, and more comprehensive methods of determining the harmful effects of support vibrations are desirable. In the first part, the undertaken approach and the results are illustrated based on the field and theoretical experience of the authors about the failure modes related to alarm level of vibrations. Here several failure modes and diagnostics observations are illustrated with the examples of real-life data. In the second part, a statistical approach based on correlation of support vs. shaft vibrations (velocity / displacement) is demonstrated in order to assess the risk of the bearing rub. The test data for few gas turbine models produced by General Electric Oil & Gas are statistically evaluated and allow to draw an experimentally based transfer function between vibrations recorded by non-contact and seismic probes. Then the vibration limit with objectives like bearing rub is scrutinized with aid of probabilistic tools. In the third part, the attention is given to a few examples of the support vibrations — among other gas turbine with rotors supported on flexible pedestals and baseplate. Here there is determined a transfer coefficient between baseplate and bearing vibrations for specific foundation configurations. Based on the test data screening as well as analysis and case studies thereof, the conclusions about more specific vibration limits in relation to the failure modes are drawn.

Acceleration Factors and Life Predictions

2020 ◽  
Vol 2020 (1) ◽  
pp. 000100-000105
Author(s):  
P.E. Chris South
Keyword(s):  
Failure Mechanism ◽  
Confidence Level ◽  
Failure Mechanisms ◽  
Software Tool ◽  
Acceleration Factor ◽  
Accelerated Life Test ◽  
Time To Failure ◽  
Confidence Bounds ◽  
Life Predictions ◽  
Equivalent Field

Abstract Acceleration factors (AF) are key to designing an effective accelerated life test (ALT). They represent the ratio of the time in field to the time in test for a particular event to occur (typically a failure event related to a specific failure mechanism). Time to failure for a device generally correlates with the amount of stress applied (the higher the stress, the quicker the device will fail), and failure models exist to mathematically define that correlation for various failure mechanisms. This allows for use of a higher stress in test than in the field, thereby providing an acceleration factor that shortens the time in test to demonstrate a failure-free time period. ALT can take the form of qualitative or quantitative testing. The latter is used to determine the life characteristics of the device with some reliability and confidence level. Usage rate acceleration and higher stress acceleration can be used. It is important to consider the design limits of the device based on its specification and material properties, and limit the stress levels in test so as not to induce failure mechanisms that the device would not otherwise have experienced in the field. ALT results are used to make life predictions for the device tested. With no failures, the test results demonstrate the required reliability and confidence level metrics for the failure mechanism of interest. With several failures, a reliability software tool can be used with the appropriate analysis method, rank method, and confidence bounds method chosen in order to extrapolate to an expected life in test. The equivalent field life is based on multiplying the expected life in test by the AF. If the field stress and/or test stress are not constant, there are multiple acceleration factors to utilize. As a result, an equivalent acceleration factor needs to be calculated and used as the AF when predicting equivalent field life.

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