Kitsets
Use kitsets to define an inventory parent item that is made up of multiple component items. Kitset parents can be held in inventory and made-to-stock, or they can be assembled while entering a sale transaction (for example, sales order entry, AR invoice entry).
You can use kitsets to set up parent items with a single-level component structure - the components cannot be kitset parent items. If you want to set up more complicated structures to support a business environment which leans more towards manufacturing, you should use the Manufacturing module.