A Bi-Level Programming Model for the Integrated Problem of Low Carbon Supplier Selection and Transportation

In this paper, we investigate an integrated problem of low-carbon supplier selection and transportation. The supplier selection decision depends on the location and energy consumption level of batching plants at the manufacturing stage. Meanwhile, ready-mixed concrete is allocated and delivered to construction sites by concrete mixer trucks at the transportation stage. A bi-level programming model for the integrated problem is established. The bi-level optimization problem is transformed into a single-level problem by KKT (Karush-Kuhn-Tucker) optimality conditions. In order to validate the proposed model, a case study is conducted based on real-world problems. Experimental results show that the proposed method efficiently solves the integrated problem and the model can not only reduce carbon emissions but also optimize transportation time.