To set this up in the Solver dialog, you should minimize cell B14 and constrain the other formulas. The Solver dialog should look like this. Minimize cell B14. Ensure D12:E12 are zero, so the flow into each warehouse equals flow out. Ensure G6 is nonnegative, so the flow from Plant 2 is within its capacity. Ensure G9:G11 is nonnegative, to satisfy the demand at each customer. Solver Parameters: Set Objective: To: Max By Changing Variable Cells: $D$5:$E$6,$D$9:SE$11 Subject to the Constraints: $D$12:$E$12-0 $G$6>=0 $G$9:$G$11-0 $B$14 Min Value Of: Make Unconstrained Variables Non-Negative Select a Solving Method: Simplex LP