Originally posted by: Cagri

Hello,

I am trying to write a CP to deal with standart parallel machine scheduling problem with sequence dependent setup times. And we have a single machine operator following this parallel process (e.g. Incubation Operation). It will be a hybrid methodology combined with MILP dealing with planning issues. I built the code already working properly without d index of day explaining each planning day. To use in this hybrid method, I would like to extend the basic model to make schedules for each day of planning horizon, simultaneously.When I add d index of Day to sequence variable, I get some errors.

Could you please help me to overcome this challenge?

Question Marks

• I am also not clear whether it is possibe to add d index of Day to sequence dvar in this concept or not?
• Do I need to call the same CP model for each planning period in a recursive manner using a loop?
• Which alternative can provide computational efficiency?

Note: Errors!, Scheduling model and data file is attached in this massage. (Errors! & OPL CP Mod, Dat, Ops Files)

Cheers!

Cagri SEL
cagrisel@gmail.com
 

Originally posted by: ol

Hello,

replace your declaration of sequence by:

dvar sequence schedule[d in Days, m in Machines] in all(d in Days, j in Jobs) opttask[d][j][m] types all(d in Days, i in Jobs) T[i];

and this will work.

Regards,

Olivier

Originally posted by: Cagri

Thanks lot for your kindly interest. It works.

But, I could not clearly understand the definition and usage of T variable. What is the fundamental mission of this variable?

int T[Jobs]=...; 

types all(d in Days, i in Jobs) T[i];

Originally posted by: ol

Hello,
The type is used to specify setup times between two operations executed on the same resource. If an operation 1 of type A is followed by an operation 2 of type B, a matrix (Setup in your model) expresses the setup times between type A and type B.
In your model this is done by the constraint:
forall(d in Days, m in Machines)
    noOverlap(schedule[d][m], Setup);
You can find a complete explanation in the user man of CPO, see "Modeling sequence-dependent setup times".
Regards,
Olivier

Originally posted by: Cagri

Thank you very much.