As I understand , pre-requisites are different from MRP Procedure steps.
The Pre-requisites for successful MRP implementation(apart from training /understanding the business processes,etc) are
1) Your Inventory Data should be accurate
2) Master Data such as safety stock, Item Data, BOM, Routing, MOQ,etc should be accurately set up.
3) Receiving and outbound /Shipments , Ordering system(SO /PO) should be online/real-time( as much as feasible).
Hope the above helps.