In a retail supply materials are normally allocated in a proportional way. When only 100 units of supply are available when the forecasted demand is 200, you want to generate a plan where each customer receives a partial delivery of the forecasted demand.
This is different from detailed scheduling in a production environment. In such an environment you will typically plan to meet the most urgent and critical customer orders first, and delay the delivery of less important customer orders.
To generate a plan with the fair share solver, you only need to change the parameter plan.solver to the value distribution.
This solver is designed for solving distribution networks. It should NOT (yet) be used on models with complex bill of materials and capacity constraints.
This example some constrained item is allocated to each of the stores where a forecast of the item exists.
With parameter plan.solver at its default value, we can see that the available inventory of 6 units is allocated to store 1A. Demand in store 1B only satisfied after the purchasing lead time.
When the parameter plan.solver is changed to distribution, we can see that the available inventory is allocated to both stores. Each store gets an allocation that is proportional to its forecasted sales.