I have 10 customers, and I produce 500 cable assemblies for them. These 500 cable assemblies are linked to 3,400 raw materials. I deliver the 500 cable assemblies to my customers on different dates throughout the year. Some raw materials are common across the cable assemblies. How can I manage the procurement of raw materials throughout the year in ERPNext? At the beginning of the year, I see all the raw materials I will need for the entire year as requirements. How can I ensure that these materials are available in my warehouse on different dates according to customer orders?