Before revision:  To attain this goal , we formulate an optimization problem to capture the C3 costs, which turns out to be a non-convex Mixed Integer Non-Linear Programming }  (MINLP) Problem. We then  propose a variant of spatial branch and bound algorithm (V-SBB), that can achieve e-global  optimal solution to the original MINLP.
After revision:  To attain this goal , we formulate an optimization problem to capture the C3 costs, which turns out to be a non-convex Mixed Integer Non-Linear Programming } (MINLP) problem with non-convex functions, which is NP-hard in general. propose a variant of spatial branch and bound algorithm (V-SBB), that can achieve e-global optimal solution to the original MINLP.