Multi-period replenishment planning with supplier assignment under a dynamic demand and stochastic lead-times
研究了多周期补货规划中，如何在多个供应商之间分配订单以最小化期望总成本，考虑了供应商价格和随机提前期的权衡，并提供了两种随机规划模型和近似求解方法。
We consider a multi-period replenishment planning problem with dynamic demand and multiple suppliers. Each supplier has its own selling price and random lead time. The objective is to decide how the demands for different periods are distributed among the pre-selected suppliers while minimising the expected total cost, which comprises holding and backlogging costs, as well as the selling price. This statement highlights the trade-off between supplier prices and uncertain lead times in replenishment planning. Two scenario-based stochastic programmes, one linear and one non-linear, are provided to simultaneously consider dispatching orders between suppliers, order crossover, and order release flexibility. The non-linear model, which relies on power sets to reduce the number of aggregated scenarios, is coupled with two approximate solution methods. The numerical experiments prove the computational effectiveness of the non-linear model. These results can be helpful for decision-makers when negotiating prices with suppliers. For instance, we can determine the purchasing cost at which we order almost 100% from a given supplier. If we now turn to the uncertainty of lead times, this study can also help negotiate with suppliers whose firms cannot decrease their selling prices and advise them, thereby reducing the variance of their lead times.