Lean Policies in Route Planning and Scheduling of Waste Collection with Fuzzy Demand

This study addresses a household waste collection routing problem with a heterogeneous fleet. The collection fleet includes hand carts and vehicles to transport wastes from houses to disposal sites. The authors attempt to enhance the system efficiency considering lean policies, which leads to minimizing the fleet size and the collection time concurrently. In reality, uncertainty of some parameters stems from environmental and living conditions. Hence, a bi-objective fuzzy possibilistic mixed integer linear programming model is developed to design an optimal collection network. To solve the model, a hybrid solution approach is applied, which combines fuzzy possibilistic programming and fuzzy multi-objective programming. Finally, several numerical examples are tested to illustrate validation of the proposed model and applicability of the applied solution approach.