Sequential multi-period models

Follow these steps to create and optimize a sequential multi-period model.

1. Add cases for each period in the multi-period sequence

   

   Each period in your multi-period sequence must correspond to a separate subcase within your model. To create a subcase:

   1. In the case list of the Model Explorer, select the case you want to be the parent of your subcase.

   2. Click Add Sub Case in the Cases group of the Home ribbon tab.

2. Link each subsequent period to the period before it

   

   Open each subcase and go to the Inventories page. Make sure the Summary tab is selected. From the Preceding Case drop-down menu, select the subcase corresponding to the period immediately before the period of this subcase. Leave set to None for the subcase corresponding to the first period.

   Select Automatically set Opening Inventory from the Final Inventory of preceding case if you want inventory values to be automatically carried over from one period to the next (recommended). Note that this option is not available if Preceding Case is set to None.

3. Set the duration of each period

   

   Set the initial and final date of each period using the two Planning Period date controls. If you have set a preceding case, the first date picker is disabled, since the initial date is automatically set to the end date of the preceding period plus one day.

4. Enter any constraints closing inventories for each period

   

   If needed, enter constraints on the maximum, minimum or fixed inventory amount for materials at the end of each period.

5. Enter any other period specific information

   

   In each period (case) enter the required period-specific information, for example period-specific prices or constraints.

6. Review links between cases

   Review the links between cases in the model's case list. Change the default view to All to see the Preceding Case column, which shows the previous case in the sequence.

   

7. Run the multi-period case stack

   In the Case Stack environment, click Run in the Modelling group of the Home ribbon tab to run the optimization.

   

   Note: Unlike normal multi-case runs, it is not possible to parallel process sequential multi-period cases. Since in a multi-period run each case depends on the previous one, they must be optimized in sequence, which may take substantially longer than parallel processing.

8. Inspect the results

   Several methods are available for comparing results between periods in a multi-period model:

   • After optimization, review the results for each case by opening the case from the case list in the Model Explorer.

   • Use the Case Stack environment. In the Model Explorer, open the desired sequence of multi-period cases using the Case Stack, optimize the cases if necessary and then use the watch sets of the model to compare the per-period results.

   • From the Case Stack environment, generate a case comparison report to show the differences in results between the different periods.