Urgent help needed: GAMS/CPlex MIP integar infeasible (BIG M, MIP, GAMS/Cplex)

GAMS
1

Dear Friends,

I am trying to implement a Mixed integer programming on GAMS/Cplex Platform. I get solution report : 10 integer infeasible. My formulation involves using of Big M constant as given below. If I remove these two equations then the solution reports seem feasible. Therefore, perhaps the problem arises due to these two equations. But, these two constraints are absolutely necessary which indicates no flow of material unless we select a location j. X(j) is a binary variable.

equation4(j)… sum((i,l),z(i,j,l))=l=bigMx(j);


equation5(j)…sum((k,l),y(j,k,l))=l=bigM1x(j);

I appreciate your help on how to deal with this. The GAMS code and the lists of equation are attached herewith.


Regards,
Syed

–
joscmalisept.gms (3.3 KB)
GAMSfriend1.pdf (68.5 KB)

2

Sorry. A variable was misplaced. Consider this attachment and suggest the Error please.

On Wednesday, September 17, 2014 10:10:37 PM UTC+9, Syed Ali wrote:

Dear Friends,

I am trying to implement a Mixed integer programming on GAMS/Cplex Platform. I get solution report : 10 integer infeasible. My formulation involves using of Big M constant as given below. If I remove these two equations then the solution reports seem feasible. Therefore, perhaps the problem arises due to these two equations. But, these two constraints are absolutely necessary which indicates no flow of material unless we select a location j. X(j) is a binary variable.

equation4(j)… sum((i,l),z(i,j,l))=l=bigMx(j);


equation5(j)…sum((k,l),y(j,k,l))=l=bigM1x(j);

I appreciate your help on how to deal with this. The GAMS code and the lists of equation are attached herewith.


Regards,
Syed

–
joscmalisept.gms (3.3 KB)