Optimization issue
Posted: Thu Dec 17, 2009 5:01 am
Hello to everyone,
I am trying to use the policy optimization tool but I do not have valid parameters to use (I belive that it is because I have the "not valid optimization instructions found" error).
I am not sure but I think that the only valid parameters are constants. The issue is that in my model I need that Vensim change some lookup functions in order to minimize the payoff.
The only characteristic of my lookup functions is that they should not exceed certain min and max values.
I try to imagine an example and this is the best I could think of: Suppose you have to minimize the total time of making a car. There are some steps to be done secuencially for finishing it. The time that takes each step to be completed depends on how many workers there are assigned in it. However, the constrain is that you have limited workers (supposing that everyone is capable of doing every process)
So I will have to find how many workers I would assign on each step in each moment --> lookup function y= f(x) where the variable x is the time and the variable y is the total number of workers in the activity y.
So based on my preview example, what I should do in Vensim is mimimize the total time varying the number of workers assigned in each step. That´s what I do not know how to do it.
If you have any suggestions or commentaries, they are very welcome.
Thanks guys,
I am trying to use the policy optimization tool but I do not have valid parameters to use (I belive that it is because I have the "not valid optimization instructions found" error).
I am not sure but I think that the only valid parameters are constants. The issue is that in my model I need that Vensim change some lookup functions in order to minimize the payoff.
The only characteristic of my lookup functions is that they should not exceed certain min and max values.
I try to imagine an example and this is the best I could think of: Suppose you have to minimize the total time of making a car. There are some steps to be done secuencially for finishing it. The time that takes each step to be completed depends on how many workers there are assigned in it. However, the constrain is that you have limited workers (supposing that everyone is capable of doing every process)
So I will have to find how many workers I would assign on each step in each moment --> lookup function y= f(x) where the variable x is the time and the variable y is the total number of workers in the activity y.
So based on my preview example, what I should do in Vensim is mimimize the total time varying the number of workers assigned in each step. That´s what I do not know how to do it.
If you have any suggestions or commentaries, they are very welcome.
Thanks guys,