Zara and H&M from the fashion retail industry

Choose any two market leaders in the sector that you are currently working or choose Zara and H&M from the fashion retail industry.
List out some of the major challenges faced by these companies regarding inventories and logistics. As a supply chain manager, what will be the strategies implemented by you, to manage these challenges
How do you think you can improve the risks associated with supply chains of these companies. Do you feel warehouse management has a major role to make these supply chains more effective ?