Use case 12 is already a good sample for project dependencies. In that use case, product1 depends on component2. As you already know, this is done by creating repository2 in configuration root.product1@Windows which checks out artifacts from latest build of root.component2@Linux. Each triggering of root.product1@Windows will cause triggering of root.component2@Linux either, which may or may not generate new build of component2 (depends on evaluation result of build necessary condition of root.component2@Linux). Of course, if your product does not need to be built on multiple platforms, you can put configuration root.component2 and root.product1 in the same QuickBuild instance on the same machine.