DSC Tech Library
This section of our technical library presents information and documentation relating to Call Center technology and Best Practices plus software and products.
DSC is a leading provider of contact center technology and software solutions as well as predictive dialer phone systems for the modern call center. Customer contact center software includes CRM software and computer telephony integration solutions. These modern products help call center phone agents communicate effectively with your customers and prospects.
The following article presents product or service information relating to call centers and customer service help desks.
Using Simulation In Call Centers
Vivek Bapat Eddie B. Pruitte, Jr., Systems Modeling Corporation
Eddie B. Pruitte, Jr., Navy Federal Credit Union
1.2 THE IMPACT OF TECHNOLOGY
Over the last decade, advances in technology have
brought about many changes in the call-center industry.
Undoubtedly, the greatest change has been the Private
Business Exchange (PBX). The once electromechanical,
step-by-step monsters have evolved into
computerized digital machines with virtually limitless
capabilities. Calls are prioritized, transferred and redirected
without human intervention.
New technology provides call-center managers with
seemingly unending options for call handling. Which is
best for the call center, vector-based routing or skillsbased
routing? Should calls be overflowed to other work
groups, or should the caller be given the option of
leaving a message to be called back?
Automatic Call Distributors (ACD) are standard in
most new PBX’s. This technology forces managers to
decide how the call should be processed. Should the call
be routed to the agent who has been available the
longest? Should agents be allowed to have after-call
work. The computer-driven PBX also affords programming
capabilities. Vectors can be written and
programmed to redirect calls to alternative work groups.
The instructions can be time sensitive and are not
bounded by location.
The Voice Response Unit (VRU) has replaced the
agent in many instances. Transactions that once required
live agents are now performed through the VRU.
The question begs, “How will these changes affect
my call center? Which technology is right for my call
center and the customers we serve?” These technologies
are powerful and dynamic, and the effect on business
can be tremendous. With all of these changes, the
evaluation of call centers is more complex than ever
before. No longer can managers, programmers or
administrators make decisions by the seat of their
pants—business is far too critical. What tool is available
that allows decision-makers an opportunity to
experiment with technology without fear of impacting
their business negatively? Simulation.
2 HOW DOES SIMULATION TECHNOLOGY
EXTEND THE CAPABILITY OF EXISTING
ANALYTICAL AND OPERATIONAL TOOLS?
2.1 ANALYTICAL TOOLS AND CALCULATORS
The most commonly used techniques for call-center
analysis are those for staffing and trunking capacity
calculations. A surprisingly large majority of these
techniques are based upon Erlang calculations (Bodin
and Dawson 1996). Erlang formulas were designed in
1917 to solve the question of how many agents would be
needed to handle the same number of calls within a
single group. The assumptions made in the Erlang-based
analysis are extremely limiting when viewed in the
context of today's call centers (Bapat, Mehrotra, and
These assumptions are rarely valid in today's callcenter
environment. Depending upon their individual
tolerance for being placed on hold for an agent, callers
do abandon, even if they are queued up. Agents differ in
their skill levels and the times needed to handle the
various calls. And the reality in today's call centers is
that call requests are varied in nature and may require
prioritization and sophisticated call handling to provide
better service. Yet many companies base complex
staffing decisions on Erlang calculations. Why? It is
because they are relatively fast and easy to perform.
A well-known criticism of Erlang calculations is that
they have consistently over-estimated staffing needs.
- Every incoming call is of the same type.
- Once a call enters a queue, it never abandons.
- Agents handle calls based on a first in, first out
- Each agent handles every call in exactly the
Studies have also shown that 60% - 70% of the costs in
call centers today are associated with staffing and human
resources. This fact, combined with the inadequacies of
Erlang-based calculations, can be enormously costly to a
call center. Furthermore, it is clear that the application
of poor analysis techniques could cause staggering
losses when applied to a call center that is growing in
size or complexity.
Many spreadsheet-based calculators have improvised
on certain aspects of Erlang calculations to provide
more realism in the usage of such calculations for
staffing. Some of them provide an element of randomness,
while others account for some forms of abandonment.
However, these patches still do not provide the
robustness of a complete solution that is provided
through simulation. In particular, many industry experts
believe that staffing issues associated with advances in
skill-based routing and network ACD's can be studied
effectively and accurately only through simulation
Erlang-based calculations are also restrictive and sometimes
incapable of analyzing business questions faced by call center
analysts and managers. For example, reengineering within call
centers predominantly involves an in-depth understanding and
analysis of call flow and process management. Quite simply,
such problems are beyond the scope of Erlang based
Systems Modeling Corporation
504 Beaver Street
Sewickley, Pennsylvania 15143, U.S.A.
Eddie B. Pruitte, Jr.
Navy Federal Credit Union
820 Follin Lane
Vienna, Virginia 22180, U.S.A.