Conditional reliability on SD

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danguzzo
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Posts: 12
Joined: Wed Jan 22, 2020 12:10 pm
Vensim version: DSS

Conditional reliability on SD

Post by danguzzo »

Good day everyone.

Using a delay to determine the outflows of a given stock creates a distribution of products proportional to the average time for outflow. In this case, the initial average age of stocks is zero, and the distribution is straightforward.

What happens when the initial age of stocks flowing into the system is higher than 0?
I got the feeling that conditional reliability* can help to determine the outflow distribution, but I don't know how to implement that.

Could anyone help me to think on a strategy to implement that rationale using delays?
Please, check the model attached. The 'reuse decommissioning' is the region of the model I need help with.

Thanks for your time in advance and let me know if I can clarify anything
Daniel!

*meaning "the probability of a system successfully completing another mission following the successful completion of a previous mission." More here
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danguzzo
Junior Member
Posts: 12
Joined: Wed Jan 22, 2020 12:10 pm
Vensim version: DSS

Re: Conditional reliability on SD

Post by danguzzo »

I am afraid my question was not really clear and I will try to restructure it.

In the model attached, the decommissioning of 'First use products' is determined by the following equation: DELAY3 (first use commissioning,average time in first use).

These products become available as 'Available used products' and some will become 'Reuse products' according to the 'fraction fit for second use'.

The challenge is the following: How can I determine the outflows of 'Reuse products' in a similar logic that I have used for 'First use products', considering their initial age is higher than 0 when they reach that status.
The average age of products on their many statuses is kept by co-flow structures.

Hope I could clarify my question now. If not, I would be glad to try again.

Regards
Daniel!
tomfid
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Joined: Wed May 24, 2006 4:54 am

Re: Conditional reliability on SD

Post by tomfid »

I think what this implies is that products in each state need some disaggregation, either with a coflow of some attribute ("extent worn out") or additional states indicating number of uses (things used once, used twice, ...).
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