The demand for subassembly S is 140 units in week 7. Each unit of S requires 1 unit of T and 1 unit of U. Each unit of T requires 1 unit of V, 1 unit of W, and 2 units of X. Finally, each unit of U requires 2 units of Y and 2 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.

what is X, Y and Z??

The product structure. The time-phased product structure. Level V 0 S 3 T T(1) U (1) X 1 S U 2 V(1) W(1) X(2) Y2) Z(2) 6 7 2 3 4 5 Time in weeks Item W Item S T U V On-Hand Inventory 20 20 40 20 On-Hand Inventory 30 25 160 40 Week 4 Lead Time (weeks) Item 1 2 3 5 6 7 S Gross req 140 On hand 20 120 Net req Order receipt 2 120 Order release 120 T Gross req 120 On hand 20 100 Net req Order receipt 1 100 Order release 100 U Gross reg 120 U Gross req 120 On hand 40 Net reg 80 2 Order receipt 80 Order release 80 V Gross req 100 On hand 20 Net req 80 2 80 Order receipt Order release 80 W Gross req On hand Net reg 3 Order receipt Order release