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
!Constraint 23: Restriction of Hybrid Center Usage
forall(j in J)do
I am really thankfull for your input and ideas on how to resolve this issue.
Best and thanks a lot in advance