order releases for all components. 15. One unit of A is made of two units of B and one unit of C. B is made of three units of D and one unit of F. C is composed of three units of B, one unit of D, and four units of E. D is made of one unit of E. Item C has a lead time of one week; items A, B, E, and F have two-week lead times; and item D has a lead time of three weeks. Lot-for-lot (L4L) lot sizing is used for items C, E, and F; lots of size 20, 40, and 160 are used for items A, B, and D, respectively. Items A, B, D, and E have on-hand (beginning) inventories of 5, 10, 100, and 100, respectively; all other items have zero beginning inventories. We are scheduled to receive 10 units of A in week 3, 20 units of B in week 7, 40 units of F in week 5, and 60 units of E in week 2; there are no other scheduled receipts. If 20 units of A are required in week 10, use the low-level-coded bill-of-materials (product structure tree) to find the necessary planned order releases for all components. 16. One unit of A is composed of two units of B and thr