Originally posted by: Elizabeth1393

Good afternoon,

I am supposed to implement a binary program in IBM ILOG CPLEX optimization studio, but I have been having some troubles, since I am not experient at this language. 
 

The model file is: 

 

 

And the data file is: 

 

 

 

The latest problem is in the last constraint, specifically here: r[j][k] * x[j][tau]  where it says "operator not available for {int}*dvar int"

 

Could somebody help me please? 

 

Thank you. 

#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi

I fixed some issues to make your model work

.mod

int n = ...;
range activities = 0..n;
 
 
{int} resources = {1} ; //{1}
 
int duration[activities] = ...;
{int} P[activities] = ...;
 
int T = ...;
int ES[activities]=...;
int LS[activities]=...;
int r[activities][resources]= ...;
//int tau;
 
range time = 0..11;
 
 
dvar int x[activities][time] in 0..1;
 
 
minimize sum (t in ES[n]..LS[n], j in activities) t*x[j,t];
 
subject to{
 
 
forall (j in activities) {
    sum (t in ES[j]..LS[j]) x[j][t] == 1;
      }      
   forall (j in activities, i in P[j]  ) {           
    sum (t in ES[j]..LS[j]) t*x[j][t] - sum(t in ES[i]..LS[i]) t*x[i][t]  >= duration[i];     
     }      
   //forall (t in 1..11) {
  //sum (j in activities) resources[j] * sum(tau in maxl(ES[j], t-duration[j])..minl(t-1, LS[j])) x[j,tau] <= 2;  
 
 // }
 forall(k in resources, t in 1..T) {
  sum(j in activities)
  sum(tau in maxl(ES[j], t-duration[j])..minl(t-1, LS[j])) r[j][k] * x[j][tau] <= 2;
 }
   }  
 

.dat

n = 8;
 
duration = [0,2,1,1,1,1,3,2,0];
r = [[0],[1],[1],[2],[2],[2],[2],[1],[0]];
 
ES = [0,0,0,2,1,3,3,2,6];
LS = [5,5,7,7,8,10,8,9,11];
T=11;
 
P = [{},{0},{0},{1},{2},{3},{3},{4},{5,6,7}];

regards

#DecisionOptimization
#OPLusingCPLEXOptimizer