Sun Devil Redi$-$Care is a small urgent care facility located near the University. Because of the high competition for student business, the manager has decided that the most effective way of competing is to emphasize short wait times. Sun Devil Redi$-$Care has even gone so far as to adopt the slogan, $$Get in$,$ Get better, Get out.$$ As the facility manager, you have decided that this slogan translates into an average customer wait time of $20$ minutes. You have collected the following data taken from a three week period of typical demand:

ca $=3\mathrm{.}35$

cp $=1\mathrm{.}35$

u $=60$ percent

tp $=4\mathrm{.}2$ minutes

Calculate the expected average waiting time for Sun Devil Redi$-$Care?

Since the expected average waiting time is greater than what you have promised, below are some possible actions that you could introduce to correct this imbalance.

A$-$ Reduce the processing time for jobs from $4\mathrm{.}2$ to less than $2$ minutes.

B$-$ Reduce one or both of the coefficients of variation by a significant enough amount.

C$-$ Reduce the utilization from $60$ to $42\mathrm{.}2$ percent by increasing the staffing levels in the health center.

D$-$ Reduce the processing time for jobs from $4\mathrm{.}2$ to $3\mathrm{.}35$ minutes.

E$-$ Reduce the utilization from $60$ to $42\mathrm{.}2$ percent by decreasing the staffing levels in the health center.

What is the expected waiting time in the current system and what actions would be expected to bring the waiting time below $20$ minutes?