Heather Adams, production manager for a Colorado exercise equipment manufacturer, needs to schedule an order for 50 Ultima Steppers, which are to be shipped in week 8. Subscripts indicate quantity required for each parent. Assume lot-for-lot ordering. Below is information about the steppers:
| Item | Lead time | On-Hand Inventory | Components |
| Stepper | 2 | 20 | A(1)B(2)C(3) |
| A | 1 | 10 | D(1)F(2) |
| B | 2 | 30 | E(1)F(3) |
| C | 3 | 10 | D(2)E(3) |
| D | 1 | 15 | |
| E | 2 | 5 | |
| F | 2 | 20 |
a) Develop a product structure for Heather.
b) Develop a time-phased structure.
c) Develop a net material requirements plan for F. Pm