You can create a package from multiple interfaces in SI.
Package Explorer
There are two ways that you can add packages to your catalog within the Package Explorer.
New Button
You can add packages "from scratch" via the New button. You can create a package, allowance, bundled cable, and solution. - all of which are types of "packages" in SI.
Clone Button
You can copy an existing package to create a new package via the Clone feature.
Product Explorer
You can select products in the Product Explorer and use the Add Items To button to add them to a package, allowance, or bundled cable.
Labor Explorer
You can select labor items in the Product Explorer and use the Add Items To button to add them to a package or allowance.
Project Editor
You can create packages within the Project Editor by selecting items and using the Add Selected Items To feature. The packages will be project-specific unless you use the Update to Catalog feature.