Question

W.L. Brown, a direct marketer of women’s clothing must determine how many telephone operators to schedule during each part of the day. The firm estimates that the number of phone calls received each hour of a typical eight-hour shift can be described by the probability distribution in the template. Each operator can handle 15 calls per hour and costs the company $20 per hour. Each phone call that is not handled is assumed to cost the company $6 in lost profit. Considering the options of employing 6, 8, 10, 12, 14, or 16 operators, use simulation to determine the number of operators that minimizes the expected hourly cost (labor costs plus lost profits).

Calls	Probability
80	0.10
120	0.40
160	0.30
200	0.15
300	0.05

Answer 1

Formulation

Two simulation runs have been shown. This will be copied downward until 500 simulations.

Sensitivity

Step-1: Write =B11 in the cell $I$10
Step-2: Select the entire array $H$10:$I$18
Step-3: Go to Data --> What-if Analysis --> Data table
Step-4: Enter $B$8 in the Colum Input Cell
Step-5: Click OK.

# of operators	Expected total cost
	315.2
2	782.32
4	614
6	491.52
8	387.28
10	305.6
12	299.04
14	297.28
16	339.44
Minimum	297.28

Note: Things will vary on each simulation instance. So, please don't check these numbers with what you got.