location and transportation model

Problems with modeling
fstone
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location and transportation model

Postby fstone » 1 week ago

Hi,
In my problem I have a node network, where nodes have different roles. Some nodes can only open like plant, some node can only open like supplier type A , some node can only open like supplier type B and some node can open like plant or supplier. I create a set with all node

set n nodes /n1*n10/

And i create a subset for each type of node

sets nj(n) node can be plant /n3,n5,n6,n9,n10/
ni(n) node can be supplier type A /n1,n2,n3,n4,n6,n7,n8/
nk(n) node can be supplier type B /n3,n4,n6,n8/

After the binary variable
Y(nj) if in node n is open a plat
X(ni) if in node n is open a supplier type A
X(nk) if in node n is open a supplier type B
A(ni,nk) if stablish link supplier and plant

Positive variable
f(ni,nj) flow between plant and supplier type A

Equation(n) is possible open one type of facilities per node
EQ2 Limit of number of plat
EQ3 Limit of number of upplier type A
EQ4 lLimit of number of upplier type B
EQ5(ni,nj,m) Logical flow restriction ;

Equation(n).. sum(nj(n),Y(nj)) + sum(ni(n),X(ni)) + sum(nk(n),Z(nk)) =e= 1 ;
EQ2.. sum(nj(n), Y(nj)) =e= NY ;
EQ3.. sum(ni(n), X(ni)) =e= NX ;
EQ4.. sum(nk(n), Z(nk)) =e= NKk ;
EQ5(ni,nj).. F(ni,nj,m) =l=bigM*A(ni,nj);

The problem is that it establishes link between nodes of subset ni and subset nj, does not consider the Equation(n) and the link is only posible between the open node supplier and the open node plant, not all.
Thanks in advance

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Renger
Posts: 33
Joined: 1 year ago

Re: location and transportation model

Postby Renger » 6 days ago

Hi
I am not sure what your exact question is as it is a little bit cryptic for me. Furthermore, your code snippet doesn't allow me to reproduce your error (see the "Rules" on how to post to this forum) . Perhaps you could repost your question using the Forum-rules.
Cheers
Renger


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