Contractor XYZ is working on a construction project where large number of doors to be installed. The master schedule for the door assembly shows $100$ units to be made in week $11,220$ units in week $14$ and $150$ units in week $16.$ There are currently $50$ units of the product in the inventory. Each door takes a week to assemble from $3$ units of part ZZ$25$ and $4$ units of part FN$24.$ Each unit of part ZZ$25$ is made in one week from $2$ units of material DD and $5$ units of material EE$.$ Part FN$24$ is assembled in $2$ weeks from $3$ units of component FF$.$ Lead times for DD$,$ EE and FF are $3,2$ and $1$ weeks respectively. Current stocks are $200$ units of ZZ$25,250$ of FN$24,120$ of DD$,400$ of EE and $200$ of FF$.$ Thecompany keeps minimum stocks of $80$ units of the door assembly, $40$ units of DD$,100$ of EE and $100$ of FF$.$ An order placed with a sub$-$contractor for $200$ units of FN$24$ is expected to arrive in period $8.$ A$.$ Draw the product structure for the door assembly. B$.$ Given an annual demand of $5,000$ units for product EE$,$ a reordering cost of $$25$ per order, and a holding cost of $$1$ per unit per year, determine the optimal lot size. C$.$ Develop a weekly production and ordering schedule to satisfy the demand for the product. Determine how many of each part or subassembly must be produced or ordered each week to satisfy MPS$.$