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if-Constraints

Question asked by simthei on Jun 18, 2015
Latest reply on Jun 19, 2015 by simthei

Hi all,

 

I'm currently working on my master thesis for network design and figured out an issue I have with two of my constraints.

 

Regard range j in J as locations for Distribution Centers, with decision variable Yj_DC. Regard range l in L as locations for Repair Collection Centers (RCC), with decision variable Yl_RCC.

 

Now, the option should be given, to co-locate DCs and RCCs, leading to Hybrid Locations which induce cost savings fj:_sav. The decision variable is Yj_Hybrid.

 

Below you find my implementation code, which does not lead to the result it should lead to. Even if for example, a DC and RCC are opened at location 1, each, the decision variable Yj_Hybrid does not equal 1.

 

I already have an idea why this is the case - nevertheless, I do not know how to implement it: What is missing from my point of view is an additional "forall(j=l)"-information in constraint 22.

 

!Constraint 22: Restriction of Hybrid Center Usage

forall(j in J, l in L)do

Yj_Hybrid(j)<=Yl_RCC(l)

end-do

 

 

!Constraint 23: Restriction of Hybrid Center Usage

forall(j in J)do

Yj_Hybrid(j)<=Yj_DC(j)

end-do

 

 

I am really thankfull for your input and ideas on how to resolve this issue.

 

Best and thanks a lot in advance

Simon

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