The demand for subassembly S is 100 units in week 7. Each unit of S requires 1 unit of T and 2 units of U. Each unit of T requires 1 unit of V, 2 units of W, and 1 unit of X. Finally, each unit of U requires 2 units of Y and 3 units of Z. One firm manufactures all items. It takes 2 weeks to make S, 1 week to make T, 2 weeks to make U, 2 weeks to make V, 3 weeks to make W, 1 week to make X, 2 weeks to make Y, and 1 week to make Z.

Construct a product tree.

Construct a gross material requirement plan.

Construct a net material requirement plan using the following on-hand inventory:

Item	S	T	U	V	W	X	Y	Z
On-hand inventory	20	20	40	30	30	25	240	40