Multi-Time Period Costs and Constraints

When building costs and constraints into multi-time period models, you can specify values in both the standard tables and in the multi-period tables. Tables that include Period as a required field are considered multi-period tables. The values can vary between the tables and across the periods, and optimization uses period-specific values. When setting costs and constraints in multi-period models, the following rules apply:

• You must define a record in the standard table. If you have only multi-period records defined, these will not be used.
• If you set a cost or constraint in a standard table, that value is used for each period, unless the cost or constraint is also set in the corresponding multi-period table. In the period(s) where the cost or constraint is also set in the multi-period table, the period-specific value acts as an override for the value in the standard table.

For example, consider the Unit Outbound Cost on the Inventory Policies and Inventory Policies Multi-Period tables. The model has 4 periods. Here are 3 cases and how the cost is applied for each period:

Case 1: Unit Outbound Cost set on the Inventory Policies table only.

Case 2: Unit Outbound Cost set on the Inventory Policies table. Inventory Policies Multi-Period records for periods 3 and 4 with Unit Outbound Cost applied.

Case 3: Unit Outbound Cost set on the Inventory Policies table. only. Inventory Policies Multi-Period records for periods 1 and 4 with Unit Outbound Cost applied.

For the Fixed Operating Cost in Sites and Work Centers, the Capacity/Fixed Cost Period and the Step Period in the Step Cost Definitions table define how these work across periods. Note that Fixed Operating Costcan still be overwritten for specific periods in the multi-period tables.