Simultaneous Equation On My Model

[JOJO Pendelchon]

Hello everyone.
As the name of topic shows I have a problem with my model.
The file that I upload is just a summary of my model.
Please help me.

[Administrator]

We can certainly help.

First try a search of the forum, as this comes up all the time.
http://www.ventanasystems.co.uk/forum/s ... mit=Search
http://www.ventanasystems.co.uk/forum/v ... multaneous

Second, if the search does not help, we will need to see the model and a brief explanation of what you are trying to do. I'm sure we can spot the error quickly.

[JOJO Pendelchon]

Thank you for your replying,Sir.
As you can see in my model I wanna create a formula that contains this situation:
Whenever the increasing goes upper than decreasing for getting back the system into balance decreasing should get oil from "USA Oil Inventory".
So,for this situation I palace an extrinsic variable named"Deficeincy Of Oil" and in this formula I palace"Increasing-decreasing".
And for decreasing I palace " If Then Else, Deficeincy>0 , USA Oil Inventory , 0"
When I run the model it says Simultaneous equation involved.
Please help me to find out the solution.

[Administrator]

You have "decreasing oil price" calculated by using "Deficeincy Of Oil". "Deficeincy Of Oil" uses "decreasing oil price". So there is no way of calculating one because you cannot calculate the other.

There has to be a delay in there somewhere which will break the simultaneous equation problem. Work out how the price decreases in reality and put that in the model.

[tomfid]

One possibility is to regard price as a stock that adjusts in response to pressures from supply/demand balance.