Creating modifications

To create a modification, select a base scenario, make changes to it and save the changes. Visum creates a model transfer file containing the differences between modification and base scenario.

1. Make sure the desired project is open (Editing basic settings of the project).

2. In the Edit project window, click the Modifications tab.

3. Then click the Create modification... icon.

Tip: Alternatively, click the Duplicate modification icon, to copy an existing modification.

The Create new modification window opens.

4. Make the desired changes.

Element	Description
Code	Short name of modification
Description	Description of modification
Group	Use this field to enter text or select an existing group. You can use the Group property to sort modifications.

Tip: You can first leave these fields empty and make or change its entries later on, in the Modifications tab.

5. Confirm with OK.

The Select the basis scenario window opens.

6. Make the desired changes.

Note: You have two options:

Use the respective buttons to select the dependent modifications and the modifications that exclude each other. In this case, the base scenario is user-defined.
Or in the list at the bottom, click a base scenario. In this case, the appropriate modifications, dependent and excluding, are automatically selected and the buttons are labeled accordingly.

Element	Description
Depending on	A modification may be dependent on other modifications. For example, when you create a new PuT line on a link that you inserted in another modification. Use the respective button to select the modifications that are dependent on the current modification. This has the following effect: If a scenario contains a dependent modification, all modifications that are dependent on it are also applied. Note You can change this setting later on (Editing the properties of a modification).
Exclusion	One modification might exclude other modifications. Click the respective button to select the modification of your choice. This settings has the effect that the excluding modifications cannot be applied to the same scenario. Note You can change this setting later on (Editing the properties of a modification).
Basis scenario	Scenario or base version you are using as a basis for modification. The modifications (dependent and excluding) are automatically selected and are later adopted into the columns of the modification. Note The user-defined scenario is automatically selected when you click a button to choose a modification.

The version file of the selected base scenario is opened. At the same time the Edit Modification window opens.

7. Make your changes to the version file.

Note: You have several options to do so:

You can, e.g., make the changes directly in the Network editor window.
You can read in additional network or demand data.
You can apply one or several model transfer files (Applying model transfer files). This way you can integrate existing model transfer files into scenario management.
You can open another version file. The differences between the selected base scenario and the version file opened are then saved to the project as a model transfer file. This allows you to integrate two version files in scenario management.

Please note the information on uniqueness of network object IDs (Information on uniqueness of IDs in modifications).

8. In the Edit modification window, click the Finish button.

The Edit project window opens again. The list now contains the new modification. The changes are saved to the project as a model transfer file. Now you can make additional changes to the project.

Tip: To open the model transfer file, click the Show modification icon.