One unit of A is made of two units of B, three units of C, and two units of D. B is composed of one unit of E and two units of F. C is made of two units of F and one unit of D. E is made of two units of D. Items A, C, D, and F have one- week lead times; B and E have lead times of two weeks. Lot- for- lot (L4L) lot sizing is used for Items A, B, C, and D; lots of size 50 and 180 are used for Items E and F, respectively. Item C has an on- hand (beginning) inventory of 15; D has an on- hand inventory of 50; all other items have zero beginning inventories. We are scheduled to receive 20 units of Item E in Week 2; there are no other scheduled receipts.

Construct simple and low- level- coded bill- of- materials (product structure tree) and indented and summarized parts lists.

If 20 units of A are required in Week 8, use the low- level- coded bill- of- materials to find the necessary planned order releases for all components.