The demand for subassembly S is 150 units in week 7 . Each unit of S requires 2 units of T and 2 units of U. Each unit of T requires 2 units 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,2 weeks to make T, 2 weeks to make U,2 weeks 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 150 units of S, there is also a demand for 20 units of U, which is a component of S. The 20 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). The time-phased product structure