The growth of the e-commerce business in Indonesia during the COVID-19 pandemic has increased the demand for last mile delivery (LMD) services. LMD activities with a large frequency of trips can increase logistics operational costs if operational handling is not carried out optimally. Optimization of LMD distribution routes is applied as an operational handling and also as a solution to the vehicle routing problem (VRP). VRP is an important problem to consider in transportation modeling where an optimum route plan is desired to obtain the minimum cost. The purpose of this paper is to optimize the last mile delivery route using the Heterogeneous Fleet Vehicle Routing Problem with Time Window (HFVRP-TW) model in urban areas. The route optimization process is carried out by developing and applying the HFVRP-TW model using data from one of the express delivery companies in Jakarta, Indonesia, and then simulating and forming several operational scenarios. The results of the analysis show that the application of route optimization with variations in vehicle types reduced operating costs by an average of 58.46% - 65.98% compared to the existing conditions. Scenario evaluation is carried out to obtain the scenario with the lowest operational cost. The evaluation results show that the best scenario is a scenario that has the closest characteristics to existing conditions, where there is no change in the type of vehicle used and optimization is only applied to operational routes. However, several other scenarios using a variety of different vehicle types still resulted in a reduction in operating costs of more than 50%.

The development of e-commerce business in Jakarta, Indonesia, in recent years has made the Last Mile Delivery (LMD) business sector develop rapidly. Increased demand for LMD makes the resulting kilometer trips even greater, resulting in negative externalities. On the other hand, logistics costs in Indonesia are only affected by vehicle operating costs and no external cost component. Optimization of LMD services that takes into account internal and external costs is needed to minimize the total cost of LMD and in reducing the impact of negative externalities. The purpose of this paper is to optimize the LMD distribution system on the Heterogeneous Fleet Vehicle Routing Problem with Time Window and External Costs (HFVRPTW-EC) models. The optimization is done by applying the HFVRPTW-EC model using data from one of the parcel delivery companies in Jakarta and then doing a simulation by forming several operational scenarios. The results show that the optimization of LMD has reduced internal and external costs by more than 50% compared to existing conditions. The detailed results show that, for the short-term program, a scenario with a one-tier distribution system and type of motorcycle vehicle can reduce total costs compared to existing conditions by 66.22% on peak day and 59.41% on off peak day. Whereas for long-term program optimization, scenarios with multiple tier distribution systems and types of motorized vehicles for drop mileage and pick up truck for stem mileage can reduce total costs by 69.23% on peak day and 60.24% on off peak day.