624 Chapter 16: Voice Techniques
Complete the following steps to forecast growth:
Step 1
Determine how many phones are currently in use.
Step 2
Determine how many employees are on campus.
Step 3
Calculate the ratio of phones to employees by dividing the number
of phones by the number of employees.
Step 4
Forecast the annual growth rate by projecting the number of
employees who are hired each year (expressed as a percentage
over the next five years).
Step 5
Use the annual growth rate forecast to calculate how many
employees the company might expect to have at the end of each
year for the next five years.
Step 6
Calculate the number of phones that are expected to be required at
one-year intervals by multiplying the projected number of year-
end employees by the forecasted annual growth rate.
Gathering Voice Traffic Data
Step 1
Contact the telephone service provider to get the following
information for two to three weeks of traffic:
Step 2
Peg counts (measurements of switch events) for incoming calls,
abandoned calls, and blocked calls (due to busy trunks).
Step 3
Grade of Service (GoS) rating for trunk groups. GoS represents
the percentage of busy signals that you are willing to accept.
Step 4
Total traffic carried per trunk group.
Step 5
Carrier rates (from phone bills).
Step 6
Obtain Call Detail Records (CDRs) or traffic reports from legacy
PBXs. CDRs typically record incoming calls but do not provide
information on calls that were blocked because all trunks
were busy.
Growth Forecast Example
The following example shows how to define and forecast growth for a small company:
·
Number of phones: 150
·
Number of employees: 200
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