I see. Thank you very much for the explanation where the error comes from. I will take a look at the sparse modelling. I was just trying to allocate the pair of distance < 30 to one proc optmodel and the pair of distance > 30 to another pro optmodel code. This was just the idea.  But I think this is not the right logic or not applicable in SAS.  ... View more

Can you pls explain if the situation is as follows; there are two types of staff models One paid for the hours worked and how they reach the site do not matter  One is paid for the hours worked (more efficient than model 1) and the travelling time from the previous working location where a VRP should be applied. the final solution should be a mix of both models there is no data on the total number of staff available Our objective is to maximise the profit  How would the code change?? ... View more

That is another valid approach but is a bit error-prone.  For example, are the 44.159 and 44.15 supposed to be the same? ... View more

Assuming that you also want z[k] = 0 to imply that x[i,j,k] = 0 and y[i,k] = 0, you can impose the following: con time_constraints_A {k in VEHICLES}: sum{i in LOCATIONS, j in LOCATIONS} t_A[i, j] * x[i, j, k] + sum{i in LOCATIONS} s_A[i] * y[i, k] <= max_time[k] * z[k]; For the second constraint, here is correct syntax: con type_link {i in LOCATIONS, j in LOCATIONS, k in VEHICLES}: v_A[i] * z[k] + v_B[i] * (1 - z[k]) >= x[i, j, k]; ... View more

"Is it also need to use round function to verify that my var has no decimal point?" No need. Firstly, You need make sure the variable is a RATIO  by your eyeball. Here I multiply 100 is for taking account of two of decimal point. E.X. 0.3456 --> 34.56 because my cutpoint is integer value, multiply 100 is to take care of .34 . .0056 is not what I care about, therefore it does not matter if using ROUNG(x,0.01) or not. "Is the action of multiply by 100 will remove the decimals ??? or need also use round???" No. not  remove decimal point. No need to use ROUND() as I said above. My GA code would not take into account of it. "as I see need also use round function." You could use ROUND(). but My code would not take care of it. So using ROUND() does not meaning anything. BTW, After you get cutoff value ,you need to transform it back into original value by multiply 0.01 . ... View more

The following documentation example shows how to approximately solve the problem: https://documentation.sas.com/doc/en/pgmsascdc/v_053/casmopt/casmopt_optmodel_examples05.htm The following article shows how to exactly solve the problem: https://communities.sas.com/t5/SAS-Communities-Library/Implementing-Column-Generation-using-SAS-Optimization/ta-p/593049 Are you able to share your data? ... View more

Always glad to help! ... View more

Can you please share your data set? ... View more

For the code I suggested, the following suffices: num FTR {PROD_IDs}; read data SECOND_FTR_PRODS into [PROD_ID] FTR; ... View more

Hi Rob Figured it out. It was a datatype issue. Fixed it and now it took all the 29 observations. It solved exactly. Thanks a lot for your support as always. You are the best ... View more

Glad to help.  Yes, your understanding is correct (assuming N=6).  You can also use the EXPAND statement to help verify what is happening.  For example: expand DesiredConstraint1; Here are the first several lines of the resulting output: Constraint DesiredConstraint1[AAA,9,DAY_1,11,DAY_2]: PROD_ASSIGN[AAA,9,DAY_1] + PROD_ASSIGN[AAA,11,DAY_2] <= 1 Constraint DesiredConstraint1[AAA,9,DAY_1,11,DAY_3]: PROD_ASSIGN[AAA,9,DAY_1] + PROD_ASSIGN[AAA,11,DAY_3] <= 1 Constraint DesiredConstraint1[AAA,9,DAY_1,12,DAY_2]: PROD_ASSIGN[AAA,9,DAY_1] + PROD_ASSIGN[AAA,12,DAY_2] <= 1 Constraint DesiredConstraint1[AAA,9,DAY_1,12,DAY_3]: PROD_ASSIGN[AAA,9,DAY_1] + PROD_ASSIGN[AAA,12,DAY_3] <= 1 Constraint DesiredConstraint1[AAA,9,DAY_1,9,DAY_3]: PROD_ASSIGN[AAA,9,DAY_1] + PROD_ASSIGN[AAA,9,DAY_3] <= 1 Constraint DesiredConstraint1[AAA,9,DAY_1,9,DAY_2]: PROD_ASSIGN[AAA,9,DAY_1] + PROD_ASSIGN[AAA,9,DAY_2] <= 1 Constraint DesiredConstraint1[AAA,9,DAY_1,10,DAY_3]: PROD_ASSIGN[AAA,9,DAY_1] + PROD_ASSIGN[AAA,10,DAY_3] <= 1 Constraint DesiredConstraint1[AAA,9,DAY_1,10,DAY_2]: PROD_ASSIGN[AAA,9,DAY_1] + PROD_ASSIGN[AAA,10,DAY_2] <= 1 ... View more

create data want from [item] x UseItem; ... View more

Rob Cannot thanks a lot for your clarity and patience. Now I completely understand. You are the best. Thanks   ... View more

A design that approximates a balanced incomplete block design should do the trick. A fully balanced design is not possible with 400 papers and your other constraints. All you need is one simple line:   %mktbibd(b=400,k=2,v=3) ... View more