Start here
Start from the layer that best matches what the issue now needs.
Start with Cases when it helps to begin from situations that look familiar before deciding what kind of support fits.
Move to Services when the issue is already active and needs clearer decision criteria, stronger review, more workable responsibility, or direct support in context.
Use Knowledge when reusable structure, a kit, or a lighter product layer may be enough before direct support becomes necessary.
Read Writing when the next useful move is sharper framing, clearer distinctions, or a better understanding of what is actually blocked.