DSC Tech Library
This section of our technical library presents information and documentation relating to Predictive Dialers and Auto Dialer software and products.
The PACER and Wizard phone systems are PC based call center phone systems that are recognized as premier inbound and outbound computer telephony systems. Features such as automatic call distribution (ACD), interactive voice response (IVR) and call recording have added a new dimension to the predictive dialer and auto dialer capabilities of these systems. These computer based dialing systems can perform various types of auto dialing campaigns simultaneously. These types include Predictive Dialing, Progressive Dialing, Preview Dialing and Dial on Demand.
Predictive Dialers – Design Considerations for Optimal Performance
Maximizing Productivity of Outbound Campaigns in Call Centers
Predictive dialers are automated systems for high frequency outbound
calling that increase productivity in call centers, i.e. where
most interactions with customers take place. Consequently,
enterprises continue to invest in technologies that improve
contact and management process and optimize the call center’s
Predictive dialers are available as turnkey, pre-packaged solutions,
or can be custom developed using toolkits. Regardless of the method
chosen, careful design consideration should be paid to ensure optimum
This white paper provides an overview of the factors affecting
the performance of a predictive dialing solution, including the
connect rate generated, the ability to distinguish between an answering
machine and a live person response, and the lead base penetration
rates accomplished. The paper also outlines hardware and software
related issues that could optimize a dialer’s performance,
and subsequently a call center’s productivity.
According to the Aberdeen Group, 70% of customer interactions
take place at the call center. With such a large percentage, it
is no wonder that companies continue investing in technologies
that facilitate the interaction with customers, even during the
present economic downturn. Spending on contact centers is forecast
to grow from $8.6 billion in 2002 to $10.9 billion by 2005, a 13%
CAGR. Within the contact center industry, the market for predictive
dialers is forecasted to grow from $717 million in 2002 to approximately
$1billion in 2005 (source: Telecommunications Market Forecast 2002).
Predictive dialers are automated systems that call a list of numbers
and turn the call over to an agent when a human responds. The use
of predictive dialers increases productivity in call centers, since
agents spend more time talking to people, rather than manually
dialing numbers, waiting for calls to go through, or hanging up
on busy signals and answering machines.
Enterprises looking to invest in predictive dialers for contact
management purposes can either select a readily available turnkey
solution, or create a custom application using a development toolkit.
Regardless of the chosen method, optimum performance of the predictive
dialer requires careful design upfront. This paper outlines the
factors that affect the performance of a predictive dialing solution,
and highlights some of the design issues related to those factors.
The connect rate is defined as the total number of calls connected
to an agent divided by the total number of calls dialed. The
connect rate is affected by several factors, including call
progress analysis (tone detection) and call transfer time.
of a predictive dialer to correctly identify the call result
it receives affects the number of appropriate calls directed
to an agent, and ultimately increases the agent’s chances
of closing a sale.
A high quality predictive dialer will accurately detect whether
a live person has answered the call or whether it encountered a
busy signal, operator intercept or an answering machine. When an
answering machine or a busy signal is detected, the number called
is kept in the database for later contact. However, when an operator
intercepts the call or a Special Information Tone (SIT) is detected,
the number is discarded from the database, not to be called again.
SIT tones are three, precise, sequential tones returned to a dialer
when a connection cannot be made with a telephone number. The most
common SIT tone is the vacant number intercept SIT (i.e.: “The
number you have dialed is not in service”).
This tone detection is performed through call progress analysis
at the hardware level. Voice cards recognize call progress tones
based on frequencies and cadence (pattern of alternating silence
and speech), which are pre-determined and stored in a defined tone
table. During call progress analysis, the voice card detects the
frequencies and cadence and compares them to the patterns stored
in the table to identify their meaning.
Since tone detection is hardware based, the selection of a telephony
card can affect the dialer’s performance. Ensure that the
card you choose or the card that ships with the prepackaged solution
has a utility that allows you to customize the call progress analysis
parameters, i.e. the tones and the frequencies to be expected under
each call progress condition such as busy, fast busy, disconnect,
no answer, and so on. Telephony cards also differ in the number
of seconds or cycles of tone pattern they ‘listen’ to
before reporting the presence of a specific tone. The longer the
card ‘listens’ to the tones, the more accurate the
detection. However, you should make sure that your card strikes
a balance between call progress analysis time frame and accuracy.
Some of the functionality provided by the telephony card – in
particular answering machine and fax detection – can also
be performed by software, which disables the card’s tone
detection capability and performs the call progress analysis directly.
Such software-based solutions can be more efficient since the software
analyzes and processes the received information faster than a hardware
Agent Transfer Time
If the predictive dialer detects a human response, the transfer
to an agent should be transparent to the receiver of the call.
This means that there shouldn’t be any delays or silence
periods between the instant the call has been answered by a prospect
to the time the agent has responded. This not only maintains a
high quality of service and minimizes nuisance calls for the receiver,
but in some cases it is a matter of abiding by the law. For example,
a new California law instituted in July 2002 states that a called
party must receive a response from the calling agent or telemarketer
within 2 seconds of the called party’s completed greeting
(Hello, Hi, etc.).
Your predictive solution should thus minimize the transfer time
as much as possible. The agent transfer time has a direct impact
on your connect rate since many individual recipients quickly realize
that they are receiving a telemarketing call when there is a noticeable
pause or silence period after they answered the call. This usually
results in hang-ups, and consequently limited list penetration.
Answering Machine Detection
Although the connect rate has a significant impact on campaign
results, it is the appropriateness of the connection that will
ultimately determine whether the transferred call will enhance
an agent’s productivity. Calls answered by a live person,
but incorrectly classified as answering machine responses – and
thus not transferred - cause call abandonment and eliminate a
potential sale from the calls transferred to an agent. (Call
abandonment occurs when a recipient terminates a call after the
dialer has determined that a live contact answered the call.)
On the other hand, the incorrect transfer of an answering machine
to an agent also reduces the productivity predictive dialers
are designed to provide.
An effective dialer minimizes call abandonment rates by ensuring
agent availability before it places a call. Predictive dialers – whether
turnkey or custom developed - should therefore provide the ability
to account for available resources and ensure that an agent is
free to answer a call before a number is dialed.
To decide whether they are connected to an answering machine or
a live person, and to potentially pass the call to an agent, predictive
dialers usually need to hear a response from the call recipient.
Usually, a short ‘Hello’ means that a live person has
answered the call, whereas a lengthy response signifies an answering
machine. Your predictive dialing application or voice card should
enable you to measure the duration of the response. Based on this
duration, your answering machine detection strategy will be determined.
Software-based detection algorithms represent a faster alternative
to hardware-based solutions. However, they sometimes require more
configuration and testing efforts. Make sure that your software
provides the flexibility to use both alternatives.
Lead-base penetration is defined as the total number of completed
calls, bad numbers, wrong numbers, sales and refusals divided
by the total amount of leads available for calling. The degree
detection accuracy plays a part here as well.
The ability of a predictive dialer to correctly identify SIT tones
or bad numbers affects the quality of your calling list. When the
predictive dialer detects a Special Information Tone (SIT), the
number called should be discarded from the database, not to be
called again. If a predictive dialer categorizes SIT tones as ‘answering
machines’ or ‘no answers’, the numbers are retained
in the database, to be re-called later. Repeat calling to the same
bad numbers prevents agents from calling other numbers in the database,
limiting the lead-base penetration process. Moreover, it reduces
the ability to maintain a ‘clean’ and useful database,
and consequently hinders the performance of a contact center.
Another factor affecting a call center’s database is the
accurate detection of fax machines. Commonly, predictive dialing
applications discard numbers that have been recognized as fax machines.
Valid telephone numbers may be deleted from your database because
the predictive dialing application has wrongly identified them
as fax machine responses, and vice versa – numbers that should
have been detected as fax machines may be retained in the database
because they have been classified as ‘no answer’ or ‘answering
machine’. Make sure that your application employs an accurate
algorithm and that it allows for the flexibility of using a hardware
and/or software based solution.
Implemented correctly, predictive dialers are an
important ingredient in call center productivity. However, the
degree of actual productivity
experienced by an implementation depends to a large degree on
design decisions and capabilities of the underlying product
To achieve optimal performance, your predictive dialing solution
should accomplish high connect rates, accurate answering and
fax machine detection capabilities and high levels of lead
which are dependent on the accuracy of your solution’s
tone detection and call transfer capabilities.