Heuristic column generation for designing an express circular packaging distribution network

Express packaging is consuming a huge amount of materials every year, which pollutes the environment and wastes resources as well. One of solutions is to build an express distribution network for circular packaging to recycle packaging materials. We present a forward and backward network that enables collection depots transport express packages to distribution centers where the wasted packaging materials are collected by recycle bins and sent back to the collection depots. Therefore, the recyclable packaging materials are detected in the collection depots, then the reusable materials are sent to the distribution centers and the others are transported back to material factories for recycling production. A mathematical model as well as a heuristic algorithm is built, based on Lagrangian relaxation and column generation, to optimize the circular packaging network. A case study has been led to test the proposed approach. The experiment results show that our solution can reduce total cost remarkably.