Basic SD Question

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jbh
Junior Member
Posts: 6
Joined: Fri Sep 16, 2005 2:26 pm

Basic SD Question

Post by jbh »

I have gained some experience over the past year with Causal Loop Diagrams (CLD) and am now trying to take a CLD to a Stock/Flow diagram. Can you point me to a good resource that will help me distinguish which variables in my model should becomd stocks, flows, and variables?

Thanks,
JBH
jwansart
Junior Member
Posts: 9
Joined: Mon Feb 20, 2006 10:49 pm

Post by jwansart »

Hi JBH,

the basic test for deciding if a variable is a stock, as far as I know, is the so called snapshot test (see e.g. Sterman's "Business Dynamics"). Just image time is freezed then what will you see? These are stocks. All the parameters changing stocks are flows. The rest is auxiliary variables.

I hope that will help you. It is not the easiest question at all.

Regards

Joerg
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