Originally posted by: bilgesu

Hi everybody;

My problem is :

I have a subscript denoted with 's', used in decision variable Xijs. I defined this s as:

tuple schedule_S{

int station;

int sequence;

};

{schedule_S} positionS=...;

 

s is referred 'sequence' in the positionS tuple.

in my data file s is given as:

positionS={ <1,3>,

<2,7>,

<3,9>,

<4,9>,

<5,9>,

<6,8>,

<7,3>,

};

 

now I need to write the decision varible Xijs (i denotes task and j denotes workstation defined in the sets). I don't know how should I write its 's' part from positionS tuple. I wrote as shown  below but it is not true...

dvar boolean x[task][workstation][positions].sequence

 

Thanks in advance;

Regards.

 

 

#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

you could compute sequences as an integer set with values 7,9,3,8 and then you would write

x[task][workstation][sequences];

regards

#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: bilgesu

thank you very much for your quick answer. but I have another tuple parameters that I should use in constraints. How tuple structure is being used in constraints I need to know.. For example Tj is the parameter that shows the set of tasks that assigned to workstations. I defined the Tj as:

Mod file:

tuple station_assignment{

int sttn;

{int} tsks;

};

{station_assignment}Tj=...;

 

data file:

Tj={<1, {1,2,5}>,

<2, {1, 2, 3, 4, 5, 6, 8}>,

<3, {2, 3, 4, 5, 6, 7, 8, 9, 10}>,

<4, {2, 3, 4, 5, 6, 7, 8, 9, 10}>,

<5, {2, 3, 4, 5, 6, 7, 8, 9, 10}>,

<6, {3, 5, 6, 7, 8, 9, 10, 11}>,

<7, {9, 10, 11}>,

};

It shows that 1, 2., and 5. tasks assigned to 1. station.  1, 2, 3, 4, 5, 6, and 8. tasks assigned to 2. station and so on...

 

In my constraint , below the sum expression  every i is element of Tj is written. I wrote its code as below. I need the tsks data from the station_assignment tuple. Is this expression of tuples in constraint is true?

forall(jin workstation, d in positiond, r in machine)

  sum (i in task: i==Tj.tsks[i]) x[i][j][d][r]<=1;

 

thanks in advance;

Regards...

#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

for each element in

tuple station_assignment{

int sttn;

{int} tsks;

};

you can do a forall or a sum on all tsks

forall(i in stations) forall(t in i.tsks)

regards

#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: bilgesu

Hi again;

I am asking to be sure that should I write my constraint as:

sum ( i in station_assignment) forall(t in i.tsks) x[i][j][d][r]<=1;

 

you wrote as forall(i in stations) forall(t in i.tsks) but i denotes tasks not stations in my model.

 

Thank you very much for your answers.

Regards...

 

 

#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi

with your data,

tuple station_assignment{

int sttn;

{int} tsks;

};

{station_assignment}Tj=...;

dvar int x[Tj][1..10];
subject to
{
sum ( i in Tj) sum(t in 1..10 : t in i.tsks) x[i][t]<=1;
}
 

works

 

regards

#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: bilgesu

Thanks for your answer. I will try it in my code.

Regards.... 

#DecisionOptimization
#OPLusingCPLEXOptimizer