# Should I process the data or add a new constraint to achieve the target?

I have an MILP as below

$$$$\begin{array}{*{35}{l}} \underset{d_{u,c}}{\max}\hspace{1mm}\hspace{1mm}\sum_{u=1}^{U}\sum_{c=1}^{C}d_{u,c}\omega_{u,c}\\ \text{}\text{subject to }\text{ C1:} \hspace{2mm}1\le \sum_{c=1}^Cd_{u,c}\le 10,\forall u, u=1,\cdots, U, \\ \text{}\hspace{16.5mm}\text{ C2:} \hspace{2mm}\sum_{u=1}^U d_{u,c}\le 50,\forall c, c=1,\cdots, C, \\ \end{array}$$$$

In addition, I want to enforce that for $$\omega_{u,c}, $$d_{u,c}=0$$.

Should I replace the entries of $$\omega_{u,c}$$ that are less than $$ to 0 or negative value, or add a new constraint?

Neither. You should delete $$d_{u,c}$$ from the model whenever $$\omega_{u,c} < t_\min$$.