The product structure. The time-phased product structure. Level V 0 S W T X T (2) U (1) S 1 Y u U Z N 2 V(1) W(2) X(2) Y(1) Z(2) 1 6 7 2 3 4 5 Time in weeks The demand for subassembly S is 90 units in week 7. Each unit of S requires 2 units of T and 1 unit of U. Each unit of T requires 1 unit of V, 2 units of W, and 2 units of X. Finally, each unit of U requires 1 unit of Y and 2 units of Z. One firm manufactures all items. It takes 2 weeks to make S, 2 weeks to make T, 2 weeks to make U, 1 week to make V, 2 weeks to make W, 1 week to make X, 2 weeks to make Y, and 2 weeks to make Z. Click the icon to view the product structure and the time-phased product structure. In addition to 90 units of S, there is also a demand for 30 units of U, which is a component of S. The 30 units of U are needed for maintenance purposes. These units are needed in week 6. Modify the gross material requirements plan to reflect this change (type 0 if the input box is not used). Week Lead Time (weeks) Item 1 2 3 4 5 6 7 S Gross req IN = Order release 2 T Gross req JL Order release 2 U U Gross req Order release N 7 2 V Gross req N Order release 1 NOT w Gross req Order release 2 Gross req E || N Order release 1 Y Gross req T Order release N z Gross req Order release 2