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A simple experiment - gone wrong.

Posted: Thu Aug 22, 2019 3:41 pm
by durhamm
Hello,

I would love some advice regarding setting up a specific experiment on Vensim PLE. I am doing this as part of personal learning at university.

version:7.3.5 on Mac
initial time :0
final time: 24
units:months

I would like to create an experiment of predicted data whereby there is a Machine A. and Machine A has part a which has a failure rate of 0.2/month. When it gets to 2.0 it needs to be replaced. So over 24 months this would happen every 10 months, = 2 times. Every time it is replaced I would like a graph to show this. In a zig-zag pattern

I have tried following tutorials and a booklet called Vensim fast guide, and although I am learning new skills, I cannot quite figure this one out :(.

I attach screenshots and a picture of how I would like the graph to look like on paper. I also attach my model - although it is not very good.
This graph in the screenshot are just my attempts and are not how i would like it to be.
Screen Shot 2019-08-22 at 16.26.02.png
Screen Shot 2019-08-22 at 16.26.02.png (41.4 KiB) Viewed 361 times
IMG_20190822_162634.jpg
IMG_20190822_162634.jpg (1.27 MiB) Viewed 361 times
Best wishes

Max

Re: A simple experiment - gone wrong.

Posted: Thu Aug 22, 2019 3:52 pm
by tomfid
What you need is a discrete event that intermittently drains/replaces the part. This might be helpful: https://vensim.com/discrete-stochastic/