Suitable formula

[mdsdoha]

Hi!

Could anyone suggest me appropriate formula? What I am trying to do is, will buy 100 cows from market and grown them up till getting milk (say, 50 weeks). then do milking for another 50 weeks. in between this process I will buy another 50 cow which will give me milk after 50 weeks. then first batch stop giving milk. Will culled 20% of cow from first batch. They will again give milk after 50 weeks. how can I make this SD loop with this description. Seeking desperate help.

waiting for kind response from someone.

[Administrator]

Have a look at the model "AGECHAIN.MDL". If you are running Windows 7, it should be in
C:\Users\Public\Vensim\help\models\Sample\EXTRA\
or
http://www.vensim.com/documentation/Mod ... ECHAIN.MDL

This will be a good model to start with. Change the variable names so that they are "cattle" instead of "population". To work out the amount of milk you get, multiply the "cattle middle" by "milk per cow per week" and you should have what you need.

[mdsdoha]

Hello Admin

Thanks for your suggestion. I tried to build my model according to your suggestion. But I failed to authenticate whether I am going right way to not. If you have time, could you please see the attached model and do some comment relating to my modelling problem. Thanks

Have a look at the model "AGECHAIN.MDL". If you are running Windows 7, it should be in
C:\Users\Public\Vensim\help\models\Sample\EXTRA\
or
http://www.vensim.com/documentation/Mod ... ECHAIN.MDL

This will be a good model to start with. Change the variable names so that they are "cattle" instead of "population". To work out the amount of milk you get, multiply the "cattle middle" by "milk per cow per week" and you should have what you need.

[mdsdoha]

Thanks for your suggestion. I tried to build my model according to your suggestion. But I failed to authenticate whether I am going right way to not. If you have time, could you please see the attached model and do some comment relating to my modelling problem. Any idea will be appreciated!