Ventana software support forum

Is it possible to perform multiple simulations of a model at once in VENSIM PLE+?

I mean, I have a model that includes several random variables of the RANDOM UNIFORM type. I'd like to know if it's possible to obtain multiple runs of the model to obtain different results.

Thank you very much

Do you mean monte-carlo simulation? That's in PLE+.

If you want to automate a certain number of runs, you would need DSS.

A quick way to do this would be to vary the noise seed in Synthesim, changing the run name each time.

You can do this one of the following ways:

A. Create a variable called NOISE SEED, with value 1 (or any other integer). Set the range to something like 1 ... 1000 and the interval to 1.
In your random functions, use seed 0, i.e. y = RANDOM UNIFORM(2.5,3.7,0)
Vary NOISE SEED with a slider.

B. Create a custom noise seed variable and vary that instead:
MySeed = 12345
y = RANDOM UNIFORM(2.5,3.7,MySeed)

Thank you so much for your replies! I truly appreciate the guidance.

I'll endeavor to put @tomfid's solution into practice. As a doctoral student without external funding, my resources are limited, and I regret to inform you that I'm unable to acquire the DSS version due to financial constraints.

Your assistance is invaluable to me, and I'm eager to explore alternative approaches to achieve my research goals.

It is possible to apply the multiple simulations with Pro version? thanks

Can you provide more details on exactly you want to do?

If you have PLE+, you can run monte-carlo/sensitivity simulations. This will automatically simulate many times and can sample from various distributions.

Sure Administrator

In my model, I've incorporated random variables using the RANDOM UNIFORM distribution to introduce randomness into certain behaviors. Following the advice of @tomfid, I've also created an auxiliary random variable to serve as the seed for the RANDOM UNIFORM variables. This has resulted in each execution of the model generating different outcomes.

Now, with this solution in place, I need to manually run multiple executions of the model and save the results of each with a different name for subsequent compilation and comparison. The question arises as to whether this process can be automated, for example, to perform 100 consecutive executions.

Automating this process would greatly benefit the efficiency of analysis and result comparison, allowing for exploration of a broader range of potential outcomes without the need for manual intervention in each execution.

Please, can you explain me why this implementation did not work? (model attached)

Try the attached using the sensitivity button rather than the simulate button.