On behalf of Ivaperez:
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Need to know if there is available a software to calculate the reliability of a system if the user enters the reliablity of the system components.

Check out:

Weibull

and:

Ivara

Message passed to Ivaperez. Thanks

Eugene, et al

We have built a system here for company wide reliability and deterioration modelling of the physical asset base.

The intention of this system is primarily to support 5 year capital submission plans throughout the water and electricity industries and we have had a great deal of success.

Send me an emaikl if this is of interest. As you could imagine this is a big system, tying in with other "big" systems.

Not something you download and evaluate.

Darth,

The user has to define the system, using e.g., a Reliability Block Diagram, which shows the interconnections and relationships in terms of the system logic. As you know, RBDs may not always resemble the process flow scheme because of the logic being context dependant e.g.,
two Relief Valves on a boiler drum each of 100% relief capacity (1oo2 configuration) will be represented in an RBD
- in parrallel for the case where the failure mode is fail-to -lift, or lifting above 110% of set pressure
- in series for the failure mode internal leak, or lifting before 90% of set pressure

Beware therefore of 'magic' software that produces answers when you put in some numbers. In any modeling activity the person doing the modeling is the key, not the number crunching software. If you buy software, make sure you have (or hire in) suitable modeling capability, else it is GIGO.

As to software, there is a wide range on offer. In the simplest case, you can build one in Excel; certainly it is powerful enough for most purposes. Reliasoft has some, and the DoE gives you some free software, see their websites. Commercial software range widely in price and capability. If you plan to make real business decisons, I suggest you consider commercial software. A search for 'reliability modeling simulation' should bring you a fair number of options. A final word of advise; dont buy software only because it is cheap. Regards.

Eugene,

There are some alternatives to RBD type packages for reliability and deterioration analysis.

In particular there are modular, (Not just the package we have built), systems that build reliability models based on deterioration at an equipment level, then coupling and calibrating these for each system and operational context.


At the end of the day much of where you need to go will depend greatly on what you need to do. If it is for cost only then you can afford to make a few errors maybe.

If it is for a one shot submission that will determine how a multi billion dollar capital progam is structured based on asset condition etc, then it becomes a whole different game.

After analysing some of the systems on the market for a few months we decided that our specific needs were outside of normal systems. Not to say that they were defficient, just that our particular clients needed other items.

Have a look at some of these links as starting points:

Military standard from the US on life prediuction for electronics (15 megabytes)

US Military reliability growth standard (5 megabytes)

Isograph

I particularly like the range of products that this company develop and deploy. In particular the RiskVu product is a winner that doesn't seem to exist in this form anywhere else.

ReliaSoft More great desktop products I think.

I have heard that EPRI also have something pretty good in this area but have never seen it. (For power systems I would imagine)

RELEX - Reliability prediction engine This is a particularly good resource I would suggest.

Riskman - ABS Consulting tools

I hope these are of some use.

Darth,

There was an error in my previous post, my apologies.

quote:

- in series for the failure mode internal leak, or lifting before 90% of set pressure

I should have said "in series for the same failure mode (fail-to-lift at 110% of set pressure) if the two PRVs were of 50% capacity each (2oo2, or 2x50%)"

I only noticed the error when I read Rui's note in a different thread. Once again, apologies for my error.

I recently downloaded the free program RAPTOR 4.0 from http://www.barringer1.com/raptor.htm

You can make a reliability block diagram from a system add failure and repair data and do a RAM simulation using monte carlo.

There is also a newer commercial version available by Arin but the functionality of this version is for me sufficient.

Barringer-NAFEM-1-14-05.pdf (227 Kb, 24 downloads) RAM RAPTOR Example