The purpose of the study is to present a solution approach to the reduction of exhaust emission by reducing fuel consumption through the time slot allocation to different service areas that minimize the time used in the delivery process. Further, it strives to create a better option solution approach that curtails the existing challenges confronting e-grocery retailers. A mathematical model is designed with appropriate constraints for the decision variables. We present an exact and a heuristic approach for this problem in which an assignment of customers’ orders to vehicles is obtained by solving a generalized assignment problem with an objective function which minimizes the time used in the delivery leading to the minimization of the fuel consumption and delivery cost. With Matlab and Cplex MILP (Mixed Integer Linear Programming), our experiment shows that by varying the number of vehicles in the fleet, our exact approach (model) can optimally solve more significant problems that can be used by existing and emerging e-grocers
