You can view items that have been associated with a particular item in the Applications Manager. You can view items that can be cross-sold with the item, items that can be substituted for an item, and items that can be up-sold for an item.
A cross-sell promotes an add-on or accessory item that, when combined with the primary item, makes a “better” package.
An up-sell promotes a more powerful or higher-level item.
Setting up a substitution association provides the ability to recognize that an ordered item can be substituted with one or more other items.