Hello,

I am working in a model that produce one batch of a chemical process that has many sub-processes. The batch horizon is 700 time intervals. During the process, one process begin for short duration (10-50 interval) who beginning time and total duration is calculated by the optimization itself. The sub-process rate of reaction follows a trajectory that is saved in a parameter of size 50 interval (less than batch horizon). Now when this process activated, it should take the first value saved in the parameter *rate(t1)* and so on. I am using MIP programming where a binary variable *sb_i(t)* is used to indicate the beginning of the sub process. The constraint look like

**set t /1 700/
set t1 /150/;
Parameter
rate(t1);
rate(t1)= (some different value)
;
Variable
sb_i(t);
Process_constraint(t);
process_constraint(t)… prcoess_mass(t)=E=process_mass(t-1)-[rate(t1)]sb1(t);*

But i think, direct way is not working due to vector different dimensions. So anybody has any idea how to proceed with such multiplication?

Thanks