Edit multi-period models

Several workflows are available to edit multi-period models. The exact workflow to use depends on how the model is being managed between different planning cycles. To make changes to multi-period models there are two fundamental workflows:

• Making changes to embedded plants.

• Making changes to original source models and replacing case definitions.

  Note: Topology changes, involving alteration to the flowsheet such as new process units, stream routings or product grades, cannot be made within the multi-period model itself. Topology changes involve changes to the master case, and so can only be made in the original source model.
  When a topology change is required, edit the original source model and recreate the multi-period model.

Make changes to embedded cases

Depending on the type of data being updated it is possible to edit the per-period definition within several different locations within the multi-period model.

• Purchases: editing the multi-period purchases grid directly edits the underlying per-period data.

• Sales: editing the multi-period sales grid directly edits the underlying per-period data.

• Constraints: editing the multi-period constraints grid directly edits the underlying per-period data.

To make large sets of changes, open the per-period case definitions within the multi-period model and edit these directly:

1. On the Plants page select the multi-period case and choose Edit Plants from the ribbon or context menu.

2. In the Case drop-down list, at the top of the left-hand side pane, choose the relevant per-period definition.

3. Edit the period.

To make changes to all periods, edit the multi-period case and change the master topology. Changes to the master topology cascade to the child cases unless they have been overridden.

Merge from source

You can make edits within the original single period source model used to build the multi-period model and then merge the changes. Changes to flowsheet topology cannot be merged.

4. Open the original single-plant model and make any necessary changes to the plant definition.

5. Use Update Case to merge the changes between the original plant and the period-specific definitions.

When merging changes, it may be necessary to merge changes into a specific target plant in the multi-period model. This is a per-period definition within the workspace.

Merge to source

After you make changes to an embedded plant model in your Network case, you may want to merge these changes into the original single-plant model. This workflow is the opposite of the one described in the previous section.

6. In the Model Explorer, select the target single-plant model.

7. Click Update Case in the Cases group of the Home ribbon tab. The Update Case dialog box opens.

8. Select the correct target case from the Target Case list.

9. Select the correct embedded plant in the left-hand slide of the dialog box. Start from Source Share and work your way down to Source Plant.

10. After the list of changes has appeared in the bottom half of the dialog box, select the changes you want to merge into the single-plant case.

11. Click Update to merge the changes.

Edit from a watch window

In a multi-period model, use Watch windows to view the per-period solutions. A separate column is shown for each period. Per-period configuration can be edited directly within the watch set, which is the same as directly opening the period-specific plant definition and editing the configuration there, or editing the period-specific constraint in the global multi-period environment.

Edit per-period definitions

In a multi-period model each period has its own per-period case, and these per-period cases all descend from a single master topology. This master topology is the same as the base case used to create the original supply chain workspace.

Period definitions including pricing, constraints and so on can be changed via the Watch window:

• Making a change to a value in a specific period only changes that value within the specific period.

• Making a change to a value in the master topology changes the value in all periods, unless it has been overridden in a specific period.