Creating variant items for classic variants

Caution Classic variants provides partial support for variant items. You can manually create and link variant items, but you cannot automatically create or update them. Variant items are fully supported (including automatic creation and updating) if you implement modular variants. If you use a custom item that has a required custom property, the property must have a default value defined or an error occurs. This applies whether you create the variant item automatically or manually. In many structures that are configured with classic variants, you define all options on the top-level item. This has the advantage of transparency—if all options are defined at the top level and sound business practices ensure consistency, the user can easily ensure the configuration is complete. When you configure the options, you determine the configuration state of all variants throughout the structure, so ensuring that a variant item is a completely configured structure. The following figure shows a typical structure of an engine. Structure of engine You can define options on the top-level Engine Family item as follows: Option Value ENG V6L, V6S TRANS M10, M50 These options determine the configuration of the lower levels of the structure through variant conditions, as shown in the following figure. Structure of engine with option values Before you create the variant item, you must configure the structure manually or with a saved variant rule, as shown in the following figure. Configured structure of engine You then create a variant item of Mainstream Module, as described later, and the resulting item is a new VI For Engine structure, as shown in the following figure. VI for engine structure Because the variant item only prunes the immediate children that are unconfigured, the Short Block item still exists in the resulting structure, but as an unconfigured item. It may seem advantageous to permanently remove the Short Block item, so that you can manage and export a minimal structure. However, this action permanently removes Short Block from Cylinder block, an item that still appears in the generic Mainstream Module. Because the Short Block item is still applicable in different configurations of Mainstream Module, removal is not an appropriate action. Another possible course of action is to create variant items at every level of the structure, or at least down to the lowest level that has any variant conditions. For example, you could create variant items for the Crankcase and Cylinder Block items, as shown in the following figure. Lower level variant items in engine structure