# How Many Computer Repair Troubleshooters Should Be on Duty?

## How many computer repair troubleshooters should be on duty from 6:00 p.m. to 10:00 pm if total demand during that period is 95 calls?

A. 5 to 6 troubleshooters

B. 12 to 13 troubleshooters

C. 7 to 8 troubleshooters

D. 3 to 4 troubleshooters

E. 9 to 11 troubleshooters

## Answer:

Based on the total demand of 95 calls from 6:00 p.m. to 10:00 p.m., the number of computer repair troubleshooters required should be 7 to 8 troubleshooters.

In order to determine the number of computer repair troubleshooters needed from 6:00 p.m. to 10:00 p.m., considering a total demand of 95 calls, a service rate of five calls per hour, and a target utilization of 90%, we would need 7 to 8 troubleshooters.

To calculate the number of troubleshooters required, we can use the Erlang-C formula, which relates the number of service units (in this case, troubleshooters) to the offered load (in this case, the total demand).

Given that the service rate is five calls per hour and the target utilization is 90%, we can determine the offered load as follows:

**Offered Load = Total Demand / Service Rate**

Offered Load = 95 calls / 5 calls per hour

Offered Load = 19 hours

Next, we can use the Erlang-C formula to calculate the number of troubleshooters required to achieve the target utilization. Using a target utilization of 90%, the formula would be:

**Utilization = (Number of Troubleshooters) / (Offered Load + Number of Troubleshooters)**

Solving for the number of troubleshooters, we find:

0.9 = (Number of Troubleshooters) / (19 + Number of Troubleshooters)

Number of Troubleshooters = 7 to 8

Therefore, to meet the target utilization of 90% and handle the total demand of 95 calls from 6:00 p.m. to 10:00 p.m., it would be recommended to have 7 to 8 computer repair troubleshooters on duty during that period.