I need to solve a Supply Chain distribution planning problem through optimizer. I am solving for a small network of warehouses & depots, you can refer the same in the attachment provided. Following are the details:
Objective: Minimize total costs
Inputs: Demand at depots (at product level), Warehouse - Depot Transportation costs, Warehouse capacity in units (total), Warehouse - Product level Lot size (Minimum quantity for dispatch)
Variable: Warehouse to Depot Shipments module
Constraints: Product demand at depot = Warehouse to depot dispatch, Warehouse dispatch <= Warehouse capacity
I have designed the optimizer without the Warehouse - Product level lot size. But I want to include this constraint, where dispatch from any warehouse to depots for any product can not go in integers, it can only be dispatched in multiples of lot size only (example: Lot size is 50, then dispatch quantity can be 50,100,200 etc.; even if the demand is 35, it will send 50 assuming that it minimizes the overall transportation cost & the warehouse has enough capacity).
How can I integrate this constraint in the optimizer to arrive at the optimal result? Any help would