# Substituting Business Components

Use the Substitutions page of the Business Components Project Editor when you have created an extended object, for example, DeptExtended from Dept, and you want to substitute in your new extended object for all instances of the base object; you want all instances of Dept to be replaced with DeptExtended.

Note: You must select the same type of Business Component in the Available and Substitute lists. You cannot, for example, substitute a view object for an entity object.

Field | Description
Available | Select the business component that you want to make a substitution for (in the above example, this would be Dept).
Substitute | Select a business component that will be making the substitution (in the above example, this would be DeptExtended).
Add | Click Add to create a new substitution. If this button is not enabled, you need to select a business component in each of the Available and Substitute lists. These two business components need to be of the same type (for example, both entity objects).
Update | Click Update to change a substitution. If this button is not enabled, you need to select a different business component in the Substitute list.
Remove | Select a substitution from the Substitutions list and click Remove to delete it.
Substitutions | This is a list of the substitutions that have been made. Select an item from this list to Update or Remove it. When you select an item from this list, the business components that comprise this substitution are highlighted in the Available and Substitute lists.