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# Reliability Engineering - Science topic

Explore the latest questions and answers in Reliability Engineering, and find Reliability Engineering experts.

Questions related to Reliability Engineering

I am finding difficulties while publishing one of my manuscript related to Maintenance Engineering. I worked very hard through out entire Year on this, and I believe that this manuscript will be very helpful and informative to any readers belong to Maintenance Engineering domain. I have submitted this in to renowned Journals but it's not been accepted. I have also updated the information as per reviewer's, However I am not satisfied with their comments.

What should I do? Please advise me.

In Reliability Engineering we use Mathematical Modelling to conclude something. We Apply the Mathematical Concepts on some Machines to analyze the lifetime or failure of the same. So, can we say Reliability Engineering is the part of Mathematical Research only?

Can I find a book or research that involves this topic?

The definition of maintenance is based on reliability, and some times we have difficult to define the best periodic and definition to maintenance, so the some software can help to define this. So I would like to know if exist any software to help with this.

Reliability and Maintainability(R&M) are important parameters to decide a product's life and its standard operations.

So, What are the latest trends that are being followed in Reliability and Maintainability Tools development?

Hi everyone, I am performing Sobol's sensitivity analysis and wondering if there is a way to set a threshold on sensitivity index so that parameters with a sensitivity index greater than the threshold is sensitive.

Many thanks!

Has anyone implemented the new Morris Method by Campolongo and Braddock in 1999 (Reliability Engineering and Systems vol 64, pg 1-12)? This is a different approach to the conventional Morris Method and it allows first order interaction to be determined.

**Does anyone know; is there any special formula for inspection or preventive maintenance intervals or scheduling, when we are applying the artificial neural network models instead of conventional methods such as weibull?**

**Thanks in advance**

What is the relation between the product reliability that is calculated in lab using ALT (Accelerated Lab Tests) and the reliability in field ?

Is it always in most cases the Lab test reliability is more than field? Can we generalise it like this?

or

In most cases the field reliability is higher compared the ALT reliability?

I just completed my Ph.D. in the Department of Mechanical Engineering Department, a specialization in Machine Design. I am interested to work as a post-doctoral fellow.

I'm currently making an investigation of how to apply RCM with Preventative Maintenance to a truck fleet of fuel transport. In my company there's not a list of functional failure or failure modes, but according to some books' authors like Dhillon, Pistalleri or Dixon, said that there are generic database failures. I was searching this kind of data in google and google scholar but didn't find anything. So, this is why I ask for you to help if you know any public generic failure database that can give my team a base of information to improve our investigation.

PD: Sorry if there's any spelling or semantic error. I'm not native English, and almost any kind of material are in this language.

Thanks,

A correct interpretation of reliability analysis is determinative for researchers and industrial developers to refine their design and also prepare proper maintenance scheduling and safety analysis. However, I still see that many designers prefer to use classical safety factors instead of reliability analysis techniques. what's your sense about this.

For example, imagine that you are going to buy a bearing and I say you this bearing's reliability is 94% for the expected life of 5 years. it means that if you test 100 bearings under normal performance, almost 6 of them should fail after 5 years. does this analysis makes sense for you in your research and development?

and if the answer is yes, how do you use the outcome of reliability analysis in your research area. the answer is important for me because I am going to start developing commercial software for reliability analysis and it is important to see what are the expectations of experts from the reliability analysis methods.

Thanks,

Sajad

I am not sure if there exists a novel method to relate the state estimation method to the prediction of a survival function or reliability distribution function, which is more like a conventional method, in prognostics. Can anyone answer the question please?

Hello. I want to start PhD in industrial engineering this year. I have a master in industrial Eng. with the grade of 3.64/4.00.

What should I do?

Which universities can I apply for?

you can see my research background and CV in my profile page.

please help me by answer and recommend this question.

Yours sincerely,

Ali

Dear all,

**Does anyone know how can I estimate the NHPP reliability function through Non-parametric method?!**

I know the

**Kernel density estimation**is widely used in this area, but seems it has very complicated theory.I was wondering if you could suggest an example or statistical software directly.

Also, I am just attaching the needed formulas of Kernel model.

Thanks for your attention.

Best/Hamzeh

Dear researchers,

I want to write an article about novel innovations in maintenance. this would be a great state of art paper which can help us in future to write about novel approaches which introduced here.

I work on some part of this paper but I need a researcher who helps me to complete the article.

Also, Professor Lorenzo Fedele help us to organize this paper.

Best Regards

Hi.

I am currently completing the final steps of my school work which is evaluation of performance reliability of Zlín aircraft on our school. The aim of my work is to prove that our fleet is safe. I have already wrote about every single failure which appeared in the last 6 years and discussed about our aircraft maintenance. The last part is calculation of reliability. I have already calculated mean time between failures (easy one) but that is not enough in my opinion. I would like to add other numbers to make the prove better. Do you know any other formulas to calculate things connected to reliability of aircraft? The data i have are types of failures, number of failures, total time flown during each year for every aircraft and calculated mean time between failures. I have found some formulas on the internet (picture added) but the description and way how to calculate it is too much for me (as i am not a mathematician student). Therefore i am looking for a simpler formulas or a program which would help me. I am really grateful for every answer.

I have problems with Polynomial Chaos Expansion Regression Method. I have some questions related with these topic and Matlab code.

If anyone help me I will be very appriciated.

My Mail adress: muratbarissarigul@gmail.com

If the problem could be solved i can give you gift or money since the problem is the main handikap of my thesis and money is not problem at all from now.

I am very confused about the formula for availability because it is given by uptime/uptime+downtime.

If f(t) represents the probability density of failure rate, then how it it possible that f(t) will follow exponential distribution whereas the failure rate is constant?

Dear all,

I really appreciate it if someone could reply my question.

The parameters based on NHPP are Shape= 0.46, Scale= 20.54.

and operation time

0, 50, 100, 200, 300, 400,..., 1000

for more detail, please find the attached file.

I do not understand why the reliability values are unreasonable!!

Thanks in advance,

Hamzeh

I need code in any programming language, preferably in matlab or R. I just dont want to code it from scratch. So please let me know if any one can help.

I have searched the definition of Mean time to failure over Google, and there is still some confusion. Some say that MTTF can also be MTBF for irreparable products. If it is also MTBF, then MTTF is 1/(Failure Rate), right? However MTTF is also the area under the Reliability function graph in some definitions.

Can someone verify these definitions?

I am interested if any of the reliability researcher has used a methodology for optimizing the time of burn-in at a technological training of electronic components and complex systems. The methodology should take into account the magnitude of thermal overload and the level of electrical overload. It would be better to allow through it can be normalized level of reliability of the products leaving burn-in procedure.

Both systems are capable of independently catering to the full load.The online system system drives the output and on its failure the switchover logic system switched to the hot standby system which are fed identical input and should produce identical outputs. The system encounters a downtime when one of the following happens:

a) Online system fails AND switch over logic Fails so cannot switch to the healthy system

b) Both system fails simulatneously due to common cause failures.

i Have attached a preliminary markov chain diagram,

The criteria weight calculation is crucial and plays an important role in the decision making process. But how to reduce the subjectivity in the decision making especially for those qualitative criteria? There exists some methods to reduce the subjective preference such as multi-criteria decision making, group technique, Delphi method, and fuzzy-based techniques. Do you have any idea on about "How to reduce the subjectivity in the decision making? " and welcome to provide some suggestions. Much obliged~

The electrified railway infrastructure set comprises of telecommunications, signalling, traction supply and the track. I intend to perform a reliability analysis on the railway infrastructure system which comprises infrastructure sets highlighted above as components. For me to complete this study I have to establish whether indeed an interdependence exists between all or some of the infrastructure sets (components) stated for the reliability analysis to be successful.

Does an interdependence exists? If so between which infrastructure sets?

A suggestion on articles that performed similar studies within the railway industry will also be of great use.

How big is the Guttman Lambda 2 big enough for us to call a reliable test? Can anyone give me a reference?

Thanks!

I've been flipping through some literature on deriving the instantaneous state probabilities of a semi Markov stochastic process. However, I haven't been able to lay hands on a worked example involving non-exponential transitions. Could you please help with links to relevant references, published or unpublished? Thanks!

**Situation**

The mechanical valves are subjected to 1000 beats per minute instead of original 100 beats per minute to measure wear.

So acceleration factor of dP/dt=accelerated frequency/working frequency=1000/100=10.

**Query**

1. How dP/dt will affect the wear?.

2. How dP/dt will affect life/durability?

How to set CPDs which are time-variant in a dynamic Bayesian network when using FullBNT toolbox?

How is the reliability of 2 dimensional consecutive k out of n systems?

Consecutive systems, k out of n, reliability, D' Moivre theory, linear consecutive systems.

Any standard reference books in this field?

Reliability analysis of railway infrastructure has looked at the different infrastructure sets individually for example the reliability of the track ,signalling and power supplies.

Is it possible to look at the whole infrastructure set as a system and perform a reliability analysis on that ?

Hi all,

I would like to know if someone know the data from a white paper/report/research paper about

-> SoftErrors: Failure in Time (FIT) rate (neutron/meoun/proton etc.) for some Flip-Flops which are based on FinFET and/or FDSOI technologies. As there are few papers available on SRAM FinFET FIT rate. Furthermore, there are few papers on CMOS FIT rate for flip flops are also available.

Thanks.

can any one suggest best voting algorithm to implement quadruple modular redudancy for the analog signals?

Is there any data available for potential exposure (#unexpected exposure) in the occupation of radiation facilities( non-nuclear facilities) like industrial radiography, food irradiation facility, radiotherapy etc.

I want to compare my data with some of the study resulting in the probability of potential exposure in above facilities. OR please give reference for the data for probability of accident in above facilities.

I am doing research on my Masters thesis on how i can improve maintenance management of the rail track using reliability analysis.I intend to perform a reliability analysis on the components that are found in the track and with that hope to establish components that can be prioritized during maintenance planning. Is this feasible ? ,if so what material would you recommend for me to read.I do not have any background in reliability engineering,but i have a solid background in Civil and Structural engineering.

Hi everyone

I am studying the First Order Reliability Method in Liquefaction Now, I have read many literature related to the calculation of this method. I have difficulty to understand the equivalent normal transformation (Rackwitz-Fiessler (1978)) two-parameters of equivalent normal transformations i.e. μ and σ . Could you help me by giving me the example and how to solve of the example, especially in liquefaction problem when we want to calculate the probability using β as reliability? if yes, please attach me the file or link.

Thank you for your attention,

Best Regard

Hello

I have few quires about modelling NBTI Trapping/Detrapping Model Based on Predictive Technology Model (PTMs) firstly for CMOS and then FinFETs for smaller tech. nodes such as 16nm/22nm/32nm/45nm.

Q1: What material PTM (CMOS and FinFETs) models used for Gate-Oxide (e.g. Aluminium oxide Al₂O₃ or Hafnium oxide HfO₂ etc...)?

Q2: Based on above material, what is the typical trap density (i.e. number of traps/cm^2) for 16nm/22nm/32nm/45nm PTMs?

Q3: What is the typical Activation Energy (Ea) value for trapped charge emission? and what is its' range?

Thank you.

Usman

The HRA is an approach widely used in the past for the assessment of the human factor in the safety of the nuclear plants. In your opinion, opportunely changed the models to evaluate it, is it possible to focus this method on the assessment of the stress in the production environment, using for example methods such as the system dynamics or others?

I Have supported the theory that the reliability of project is related with a technical technological reliability- human reliability and environmental factors

What are the main factors we need to account for mathematically predicting (FEM) fatigue life and reliability of Mechanical heart valve?

In addition to the factors like "a)surface finish b)size c)temperature d)load factor e)fatigue strength reduction factor f)Stress avg and max" along with "Goodmann relation equations" what are the other critical factors needed to numerically predict the life in number of cycles.

Also how body fluids like blood effect the fatigue of materials, as the SN curve we generate is at room temperature and at air surroundings. So can we use the SN curve at air for predicting life of an implant socked in blood by using any correction factor?

Reliability Engineering. In development product.

Could you tell me an artificial method to calculate the reliability of the structure?

I study the reliability of the system and use the RBD (Reliability Block Diagram). I should find the failure rate but I couldn't be sure of the data set size. Is there any rule about size?

we will find the liner relationship between reliability and risk in the maintenance, Determination index that show weight tow criteria: risk and reliability

So far I have used 0,10,20,40,50 for DALs E,D,C,B,A respectively.

Any comments on this ?

I have two Markov reliability model for fault tolerant mechanism and I want to achieve the sensitivity solutions of these models through perturbation theory.

I am currently working on my final year project which entitles " Probabilistic Life Cycle Cost in Pipeline System." I am thinking of using ANFIS to determine the cost.

Does safety always increase by increasing system reliability?

Some of them are DFT and BIST. What are others?

I find very often that professional and laymen are using the wording “risk” and “reliability” as having the same meaning. As I speak few languages, I have the impression that this perception of the subjects is cross cultural phenomena.

A lot of various paper discuss the need of uncertainty decomposition into aleatoric and epistemic. In the context of reliability and risk analysis, the uncertainty quantification is commonly refered to be very significant in order to achieve more accurate results.

I know how to determine the weibull distribution, but I don’t see the usage or the contribution that this analysis can do during the implementation of reliability centered maintenance.