Originally posted by: mGlass

Good afternoon,

My model does not display any error but it does not follow the constraints.

Can you please help?

Thank you so very much,

M

Hi,

can you also attach the .dat ?

regards

Originally posted by: mGlass

Here it is!

hi

and the excel file ?

regards

Originally posted by: mGlass

Here they are,:

The data set is not really small, though..

Thank you for your time!

Ps:I've made some small changes on my .dat file

Hi,

yes that is normal because your model is not feasible and you get a relaxed solution.

You have a nice video at https://www.youtube.com/watch?v=tUALbhJ2xWY

and in the documentation I recommend IDE and OPL > CPLEX Studio IDE > IDE Tutorials > Relaxing infeasible models

regards

Originally posted by: mGlass

Good morning, 

Thank you so much for the suggestions. 

However, my problem is that the model should not be infeasible because the supplier does not have any constrain. Hence, the plant requirements should always be possible to fulfill.

Best regards, 

M

Hi,

you get a conflict at least:

Line    In conflict    Element (2)
109    Yes    StockinClients_Returns#0#2#0
113    Yes    StockinClients#0#2#0

If you comment

//  forall (i in clients, p in pallets, t in aperiods)
//  StockinClients_Returns:
//  sum(j in plants) x[i][j][p][t] <= stockinclient[i][p][t] ;
//  
//  forall (i in clients, p in pallets,t in aperiods)
//  StockinClients:
//  stockinclient[i][p][t]==stockinclient[i][p][t-1]-sum (j in plants)x[i][j][p][t] +xpa[i][p][t];
 

then your model gets feasible

regards

Originally posted by: mGlass

Thank you so much!
Indeed I had the constraints wrong!

Originally posted by: mGlass

I'm sorry, I still have a conflict:

  forall (i in clients, p in pallets, t in aperiods)

  StockinClients_Returns:

  sum(j in plants)x[i][j][p][t] <= stockinclient[i][p][t-1] +xpa[i][p][t];

  forall (i in clients, p in pallets,t in aperiods)

  StockinClients:

  stockinclient[i][p][t]==stockinclient[i][p][t-1]-sum(j in plants)(x[i][j][p][t])+xpa[i][p][t];

How can I have a conflict in these 2 expressions?

If I join them, I'll have: stockinclient[i][p][t] >= 0.

These constraints were just to assure that:

1. the client cannot ship more than what it has in stock

2. keep track of the stock (stock= stock in the previous period +  what the clieent receives - what the client sends