Planning for supply chain with seasonal variable delivery time

The fluctuation of the seasonal variable delivery time significantly impacts the operating costs of production and distribution systems. This paper finds that a non-linear deliver time function which has a non-zero second derivative can simulate the practical situation more than linear function which has a zero second derivative based on practical data. And this paper focuses on a supply chain in which the retailer requires a small-lot at a fixed interval, the manufacturer sets up a distribution center to satisfy the demand, and the manufacture facility is far from the retailer. A search algorithm for finding the optimal production lot and ordering quantity in a system of non-linear deliver times is proposed. The sensitivity analysis shows that cost savings can be achieved by planning production cycles according to the acceleration of deliver time changes and in-transit costs.