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Thank you so much! I'm sure it will be useful!

The goal of the model is to find the time t in which the harm definitely happens (Pr=1). What I'm doing is a criticality analysis. Usually this is done assuming that each failure is independent from the others (thinking as if they were "elements in series" and that the failure rate of the ...

I tried with Max function and If then else function (If the else( P(A)+P(B)-P(A)*P(B) <1 , P(A)+P(B)-P(A)*P(B), 1)). But nothing is change.

That's right, in fact the Frequency rate is expressed in this manner. These values, unit=1/year, is used as an "mean value" in the RANDOM WEIBULL and RANDOM EXPONENTIAL functions (to express sudden failures). But when I combine different pdf, Vensim return me functions that doesn't stop at...

And what would I have to do to get a state function? I'd need it to give me back the probability of occurrence within the final time considered.Some are exponential and some Weibull, this depends only on the physical meaning of the variables (the two Weibull represent the wear of a component).

So, the model is as follows: I am studying the effects that failure modes, found after an FMEA analysis, of an endoscope on the probability of harm (intended for patient, nurse or surgeon). These failure modes have causes with failure frequencies (1/Year), considered as constants. Some failure proba...

There is no limit field. The equation logic itself has to implement the logic. You can always constrain things with something like MIN(1,MAX(0,expression)), but if your pdf doesn't integrate to [0,1] you probably have a problem with the expression itself. Maybe the problem is in De Morgan's formula...

Ah ok, and how can I implement a limit in a equation? There is a specific field? I understand that the limit in a editor return me only a warning message, but I'd like to have a "normal" pdf graphic. So, the Variables named "Frequency.." are my Lambda. Beta and Beta Valve are the...

Sorry, I exceeds the maximum number of file to send

How stupid! I didn't actually see the models on the side! Thank you very much, now I've set the problem! :D :D :D However, there's still one problem: When I combine more pdfs between them (I use Total probability theorems in "Equation"), even if I put the Max to 1, the graph keeps going be...

Hello, everybody! I'm a new member, my name is Giuseppe. Nice to meet you all! I'm a student of master's degree, but I' m having some problems using Vensim for my thesis and that's why I joined here. More precisely, I don't really understand how Random Function works. Since my case study includes so...