$14\mathrm{.}5)$ 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$.$ A$.$ Construct a product structure. Identify all levels, parents, and components.