System Conversion to SAP S/4HANA from SAP ERP on HANA

hi,

is there any roadmap to help with the conversion to s/4HANA? especially from SAP ECC on Hana. Do we really need solman for this conversion? We already have hana DB in Action. What are the main steps and Tools that we can use?

I have another question, hana test /migration cockpit, do we need an S/4hanan system to be able use them? Is there a way to perform these Steps in SAP ERP?

back to solman. Are there any other ways to use the Maintenance Planner without the Solution Manager?

thank you in Advance