Problem $10\mathrm{.}6($page $443)$: The PM Computer Company makes build$-$to$-$order $($BTO$)$ computers at its distribution center year round. The following table shows the average value $($in $ millions$)$ of component parts, work$-$in$-$process, and finished computers at the DC for the past four years:

Problem $10\mathrm{.}6$

a$.$ Determine the number of inventory turns and the days of supply for each year.

b$.$ As the company has grown, does it appear that the company$$s supply chain performance has improved? Explain your answer.

c$.$ If the company wants to improve its supply chain performance, what items should it focus on$?$ Why?