A part kit is a product that is comprised of multiple components. To create a part kit go to Parts / Part Kits and add. Once the partkit is created then add the needed components which are actually preset up skus. There is also an option to add component order quantities. This only relates to the quantity when ordering the component through the kit.
When adding the items to the storefront, you only need to add the part kit sku to the part category. The components will automatically be available to the production team when the order has been submitted. The components of the partkit will be broken out into their own order line. The component and its corresponding partkit will be listed.