- a.jpg (236.4 KiB) Viewed 514 times
Reverse engineering
Reverse engineering
Hello. I want to ask the advice of experts. How to transform a big casual lop diagram image to the vensim model. Are there any automated solutions? How to speed up the manual rewriting process?
Re: Reverse engineering
Generally a causal loop diagram can't be translated automatically to a model, because it simply doesn't contain enough information.
The COIN diagram you posted actually has an underlying model that is much larger.
https://metasd.com/2010/04/hypnotizing-chickens/
You should be able to turn a CLD into a model, if you have some domain knowledge and are willing to make some commonsense decisions about the structure.
The key thing is to work in small chunks - pick an area of the model, or a feedback loop, that is of interest, and work on that, rather than trying to do the whole thing. The first step will be to identify the stocks, and describe how they work in a more operational way.
The COIN diagram you posted actually has an underlying model that is much larger.
https://metasd.com/2010/04/hypnotizing-chickens/
You should be able to turn a CLD into a model, if you have some domain knowledge and are willing to make some commonsense decisions about the structure.
The key thing is to work in small chunks - pick an area of the model, or a feedback loop, that is of interest, and work on that, rather than trying to do the whole thing. The first step will be to identify the stocks, and describe how they work in a more operational way.
/*
Advice to posters (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Blog: http://blog.metasd.com
Model library: http://models.metasd.com
Bookmarks: http://delicious.com/tomfid/SystemDynamics
*/
Advice to posters (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Blog: http://blog.metasd.com
Model library: http://models.metasd.com
Bookmarks: http://delicious.com/tomfid/SystemDynamics
*/
Re: Reverse engineering
HI
The COIN model discussed years ago in the SDS forum when it was still active, is for me a good example of an impressive model, that has no chance of ever being useful to anything or anybody except its author. Exposing the reasons would take me a time that I am no more ready to spend, because my experience tells me that SD people will not understand them because they do not like them.
JJ
The COIN model discussed years ago in the SDS forum when it was still active, is for me a good example of an impressive model, that has no chance of ever being useful to anything or anybody except its author. Exposing the reasons would take me a time that I am no more ready to spend, because my experience tells me that SD people will not understand them because they do not like them.
JJ
Re: Reverse engineering
Hi
I think that it is possible to build useful models with SD and with that type of problems but not with the way that they are generally built, tested, analyzed, used and eventually implemented (very rarely). The behavior’ shape of the system predicted by the model is never compared with the real behavior’ shape of the system as it happens in the reality after a certain time corresponding with the horizon of the model. I have never seen a public study doing this and I think that missing this opportunity ruins any chance of validating a model and understanding the system it is studying.
JJ
I think that it is possible to build useful models with SD and with that type of problems but not with the way that they are generally built, tested, analyzed, used and eventually implemented (very rarely). The behavior’ shape of the system predicted by the model is never compared with the real behavior’ shape of the system as it happens in the reality after a certain time corresponding with the horizon of the model. I have never seen a public study doing this and I think that missing this opportunity ruins any chance of validating a model and understanding the system it is studying.
JJ