Wastewater treatment sims

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odlanierzdenitram
Newbie
Posts: 1
Joined: Wed Feb 04, 2009 11:03 pm

Wastewater treatment sims

Post by odlanierzdenitram »

Hi everyone. Glad to be here. I just discovered this interesting and powerful tool. The first idea I want to tap is some kind of sim model for wastewater treatment systems.

Are there any ideas the veterans can tip me with to get started?

Thanks and best of regards,

Odlanier
LAUJJL
Senior Member
Posts: 1477
Joined: Fri May 23, 2003 10:09 am
Vensim version: DSS

Wastewater

Post by LAUJJL »

Hi

SD is certainly a powerful tool, but it is difficult to learn how to master it in a useful way.
The only advice I can give is to keep models simple.
From now 7 years of practice, the single characteristic of models that have benn useful for me, is simplicity.
Simple models are quick to build, easy to modify, easy to anlyze, easy to communicate and easy to use again when time has passed and you have forgotten how they work.
At what level a model becomes complicate?
It depends on the experience and the time available of the modeller. For example, for me, who has lots of other things to do, if the model has more than 100 elements, I start to consider the possibility that the purpose of the model is not precise enough and that it may be useful to reconsider it.
If the model has more than 150 elements, it is sure that for me it is too big and has to be reconsidered.
I have just reconsidered a model that had grown up to 320 elements with a subscript with 100 elements.
That model was giving interesting results but poor understanding and having results with no deep understanding how they were generated is bad practice.
Of course I could spent a lot of time, analyzing the model but I have not so much time.
I reconsidered completely the purpose and its definition and I built in approximately 10 hours a model with 80 elements and no subscripts that gives nearly the same results and is incomparably easier to understand and analyze.
The former model with 320 elements took me aproximately 200 hours to build!
So for me productivity equals simplicity.
Regards.
JJ
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