@DionisMotor Your post is now published.  ... View more

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