Agile or Hybrid Agile - Delivering System Migration - System Upgrade

Questions 1

What is the SAP recommended attack for ERP Delivering System migration and method upgrade. Does SAP urge Agile oregon Hybrid Agile approach?

Could you delight supply nexus to documentation connected the SAP recommendations? 

Please spot the attached screenshot. 

Questions 2

What is the SAP recommended attack for improvement of Fiori apps. Does SAP urge Agile oregon Hybrid Agile approach?

Could you delight supply nexus to documentation connected the SAP recommendations? 

Please spot the attached screenshot.

Thank you 

Could you delight supply resources to consult