Excel Solver, Integer Programming

[westphalia]

Hi folks, I hope some of you are familiar with modelling, integer programming and excel solver for doing this.

My model is a scheduling model, which minimizes the total setup times and makes a scheduling according to that.

minimize Xa,b*Ca,b + Xb,a*Cb,a + Xa,c*Ca,c + Xc,a*Cc,a + Xa,b*Ca,b + Xb,a*Cb,a + Xb,c*Cb,c + Xc,b*Cc,b

constraints

Xa,b + Xb,c = 0 or 2
Xa,c + Xc,b = 0 or 2
Xb,c + Xc,a = 0 or 2
Xb,a + Xa,c = 0 or 2
Xc,a + Xa,b = 0 or 2
Xc,b + Xb,a = 0 or 2

Xa,b = must be 0 or 1
........ all other variables are as Xa,b


Folks, for people who are not familiar let me explain. Xa,b and such are variables. These can be either 1 or 0. It is used for making a schedule among a,b and c. Ca,b and such are setup time if we are producing a currently and we change production to b.

I hope someone can help me...

 

[PaddyD]

Hi.

Not sure exactly what your question is. You say you have a model ('My model is a scheduling model...") Do you have this implemented in excel yet & want help with solving it, or are you asking us to help you with the implementation given the model description? or maybe something else?

 

[westphalia]

I dont know how to implement it with excel solver, I opened excel solver but i got totally confused. Besides I couldnt see an option for integer programming (Xs must be 0 or 1)

 

[PaddyD]

re the binary constraint, it's under the subject to constraint 'add' button in the middle drop down of the new dialog box that pops up.

re the model I'll get back to you (though proper work is going to intervene for a while).

 

[westphalia]

Hi, thanks Paddy i had some advance thanks to you.

But i have a problem now, how can I tell the excel that Xb,a + Xa,c = 0 or 2

there is only =<

 

[tusharm]

Xba=Xac

Hi, thanks Paddy i had some advance thanks to you.

But i have a problem now, how can I tell the excel that Xb,a + Xa,c = 0 or 2

there is only =<

 

[westphalia]

Oh, of course! Thanks!

 

[PaddyD]

So - have you got this sorted? If you need more, post back with details of how you're implementing the model.