Hello, I need help with building an MRP. I get really confused as to where the numbers are coming from so a step-by-step would be very helpful in understanding this concept.

Sudden Brakes, a bicycle shop, sells and services bicycles. Due to the weeklong Ragbrai event that happens in the third week of July of that year, there have been heavy demands for brake assemblies as people start training for the event right from the first week of May. May has 5 weeks; June has 4 weeks. A brake assembly for a bicycle is made of 2 units of A and 4 units of B. B is made of 2 units of D. A is made of 3 units of C and 4 of D. Unit D is made of 2 units of E. All units have a lead time of 1 week except D which takes 2 weeks; Suda, the owner, expects that his demand would be 250 units of brake assemblies every other week starting from the beginning week of May and expects an increase of 50% during the event. He wants to have a safety stock of 125 units of the brake assembly and has 400 units as initial inventory. All components are procured based on net requirements. Show the BOM with levels as a product structure and develop an MRP for Suda.

I believe I have BOM:

Level 0 - Brake Assembly

Level 1 - A(2) | B(4)

Level 2 - C(3) D(4) | D(2)

Level 3 - E(2) | E(2)