Multi-objective optimization of recycling and remanufacturing supply chain logistics network with scalable facility under uncertainty
Recycling and remanufacturing logistics network affects the scale and efficiency of sustainable development of the manufacturing industry. This paper designs a multi-level closed-loop supply chain network with supplier, manufacturer, recycling centers, preprocessing centers and processing centers. An improved nonlinear grey Bernoulli-Markov model is developed to predict the recycled quantity. The capacity of recycling center and preprocessing center, the demand of manufacturer and the inventory of preprocessing center are formulated as constraints. A dynamic multi-objective model, which is based on scalable logistics facilities, takes into account the minimization of system operating costs and minimization of time costs related to the out-of-stock and inventory in each operating cycle. This model realizes the dynamic selection of the scale of facilities. Objective weighted genetic algorithm is adopted to transform multi-objective optimization problem into a single-objective. A scrap automobile products calculations are analyzed to verify the effectiveness and practicability of this model.
A Markov Chain Formulation for the Grocery Item Picking Process
A major chunk of Walmart business (and most of its markets outside the US) comes from Grocery. Customers place orders online which are then delivered to the shipping address or collected by customers from the store (CnC).
What is common to both modes of fulfillment of an order?
It is the process of picking items done by associates in the store. While the actual process has many complexities like downloading of online orders into the store, figuring out locations of items in store, generation of substitutes, generating optimized number of containers to fulfil an order, generating optimized pickwalks for associates across the store etc., the basic operation performed by the associate is to look at different items in an order (typically between 50–70 items) and add them to the containers.