Please help me to figure out the Y and Z.

The demand for subassembly S is 80 units in week 7. Each unit ofS requires 2 units ofT and 1 unit of U. Each unit ofT requires 1 unit ofV, 1 unit of W, and 1 unit of X. Finally, each unit of U requires 2 units on and 3 units of 2. One rm 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. [i Click the icon to View the product structure and the time-phased product structure. @ Click the icon to View the on-hand inventory. Construct a net material requirements plan using onhand inventory (enter your responses as whole numbers). Week Lead Time Item 1 2 3 4 5 6 7 (weeks) S Gross req 80 On hand 20 Net req 6O 2 Order receipt 60 Order release 60 T Gross req 120 On hand 20 Net req 100 1 Order receipt 100 Order release 100 The demand for subassembly S is 80 units in week 7. Each unit ofS requires 2 units ofT and 1 unit of U. Each unit ofT requires 1 unit of V, 1 unit of W, and 1 unit of X. Finally, ea requires 2 units of Y and 3 units of 2. One rm 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 2 weeks to make Y, an M Click the icon to vi X I More Info a Click the icon to vi Construct a net materi The product structure. The time-phased product structure. Lead Time Level 0' V Q (weeks) 0 S w T Q X q o 1 T