Time Intervals between Period

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Inthanongsone
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Posts: 34
Joined: Thu Jan 28, 2016 6:01 pm
Vensim version: DSS

Time Intervals between Period

Post by Inthanongsone »

Hi Folks,

I am trying to figure out how to solve the time interval problem..

Let say I've four different time scale
(1) base scale time (year)----I've Initial investment cost occured in this time period (It is supposed to occur only on construction time)
(2) deferment time (year)----I've deferment cost occurred in this time period and it is supposed to occur when the defer time is greater than zero.
(3) expand time (year)----I've expansion cost occurred in this time period and it is supposed to occur when the expansion time is greater than zero.
(4) closedown time (year)----I've closedown cost occurred in this time period and it is supposed to occur when the closedown time time is greater than zero.

I would like to have graph like the one I've attached in this post but it was not...I've tried to change the functions but it didn't work.
Could any help give some suggestion and advice to this problems.

I've attached the model hereby this post.

I appreciate any help.

Thank you very much.

Regards,
Inthan
IdealGraph
IdealGraph
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tomfid
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Posts: 3806
Joined: Wed May 24, 2006 4:54 am

Re: Time Intervals between Period

Post by tomfid »

I think you need to be more clear about mine capacity, with an explicit stock that's increased by events like a capacity expansion, with an associated cost. You might look at http://vensim.com/discrete-stochastic/.

Also, your cash flow formulation will inject the cost of expansion (etc.) continuously, not in a pulse as it ought to.

I would studiously avoid multilevel nested IF THEN ELSE statements. Even if it's correct, no one (not even you) can really read the equation. Better to decompose it into several additive terms or something.
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