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.
Call Center Simulation Modeling:
By Vijay Mehrotra, Department of Decision Sciences
Methods, Challenges, And Opportunities
College of Business - San Francisco State University
Jason Fama, Engineering Group, Blue Pumpkin Software Inc.
Using stochastic models to plan call center operations,
schedule call center staff efficiently, and analyze projected
performance is not a new phenomenon, dating back to Erlang's
work in the early twentieth century. However, several
factors have recently conspired to increase demand for
call center simulation analysis.
- Increasing complexity in call traffic, coupled with
the almost ubiquitous use of Skill-Based Routing.
- Rapid change in operations due to increased
merger and acquisition activity, business volatility,
outsourcing options, and multiple customer
channels (inbound phone, outbound phone, email,
web, chat) to support.
- Cheaper, faster desktop computing, combined
with specialized call center simulation applications
that are now commercially available.
In this tutorial, we will provide an overview of call center
simulation models, highlighting typical inputs and data
sources, modeling challenges, and key model outputs. In
the process, we will also present an interesting “realworld”
example of effective use of call center simulation.
1 INTRODUCTION: “WHY CALL CENTERS?”
The trend in our economy from manufacturing towards
services is well documented. One notable facet of this
transition towards services has been the explosion of the
call center industry.
Mehrotra (1997) defines call centers as “Any group
whose principal business is talking on the telephone to customers
or prospects.” In this paper, we will refer to the
individuals who talk on the phone with customers as
While the size of the industry is difficult to accurately
determine, a plethora of statistics from diverse sources reflect
that fact that this is a huge and growing global industry.
Most stunning: Mandelbaum (2001) cites a study that
an estimated 3% of the United States population works in
this industry. Most recent: an explosion of outsourced call
centers springing up in India, the Philippines, the Caribbean,
and Latin America, serving overseas customers in the
United States and Western Europe as well as growing domestic
From a mathematical perspective, call centers are interesting
for a variety of reasons:
Thus, call centers can be thought of as stochastic systems
with multiple queues and multiple customer types.
As we discuss below, there are great challenges associated
with managing these systems effectively.
- Call centers typically handle more than one type
of call, with each distinct call type referred to as a
“queue” (as discussed below, this usage is not
consistent with our normal definition of a queue).
Inbound calls within each queue arrive at random
over the course of time.
- In many centers, agents make outbound calls to
customers, either proactively (typically for telemarketing
or collections activities) or as a followup
to previous inbound calls.
- Each call is of a random duration, as is the work
(data entry, documentation, research, etc.) that
agents must do after completing the phone call.
- Through Automatic Call Distribution (“ACD”)
and Computer Telephony Interaction (“CTI”) devices,
inbound calls can be routed to agents,
groups, and/or locations, with advancements in
these routing technology supporting more and
more sophisticated logic over time.
- Individual agents can be skilled to handle one
type of call, several types of calls, or all types of
calls, with different priorities and preferences
specified in the routing logic.
To summarize, call centers are of interest both because
of the sheer size of the industry, both in the United States
and overseas, and because of the operational and mathematical
complexity associated with these operations, which
makes it difficult for decision makers to understand system
dynamics without effective modeling.
Department of Decision Sciences
College of Business
San Francisco State University
1600 Holloway Avenue
San Francisco, CA 94123, U.S.A.
Jason Fama Engineering Group
Blue Pumpkin Software Inc.
884 Hermosa Court
Sunnyvale, CA 94085, U.S.A.