Title: Method for estimating telephony system-queue waiting time in an agent level routing environment
Abstract: A system for estimating call waiting time for a call in a queue takes into account multiple queues wherein agents are shared between queues, abandoned call history, and virtual and priority queues. The system in a preferred embodiment is a computer-telephony integration (CTI) software application adapted to execute on a CTI processor, which may be coupled to switching equipment at network level in a connection-oriented, switched telephony (COST) network or to a switch at call-center level, or both.
Patent Number: 6,898,190 Issued on 05/24/2005 to Shtivelman, et al.
| Inventors:
|
Shtivelman; Yuri (Belmont, CA);
Anisimov; Nikolay A. (Walnut Creek, CA);
Pogossians; Gregory (Palo Alto, CA);
Deryugin; Vladimir N. (Lafayette, CA);
Balkin; Dmytro G. (San Bruno, CA);
Stoilov; Luben Gueorguiev (Fairfax, CA)
|
| Assignee:
|
Genesys Telecommunications (Daly City, CA)
|
| Appl. No.:
|
730416 |
| Filed:
|
December 4, 2000 |
| Current U.S. Class: |
370/270; 370/252; 370/412; 379/266.01; 379/309 |
| Intern'l Class: |
H04Q 011/00; H04L012/16 |
| Field of Search: |
370/259,270,352-356,412,252,415,389,229,429
379/265.01,265.02,242,265.05,265.07,265.08,265.09,265.1,265.11,265.14,266.01,266.03,266.06,266.08,309,308,268,272
|
References Cited [Referenced By]
U.S. Patent Documents
Primary Examiner: Patel; Ajit
Attorney, Agent or Firm: Boys; Donald R., Central Coast Patent Agency, Inc.
Parent Case Text
CROSS-REFERENCE TO RELATED DOCUMENTS
The present application is a divisional application of patent application Ser.
No. 09/209,306 filed Dec. 11, 1998, now U.S. Pat. No. 6,157,655. The prior application
is incorporated herein by reference in its entirety.
Claims
1. A method for estimating waiting time for a call in a call-waiting queue, comprising
steps of:
(a) multiplying the number of calls ahead of the call by an average call handling
time; and
(b) dividing the result from step (a) by an effective number of agents assigned
to the queue.
2. The method of claim 1 by the not-abandoned call rate.
3. A call routing system comprising:
a call switching apparatus; and
a facility enabling the switching apparatus to maintain routing queues;
wherein the system determines a wait time by multiplying the number of calls
ahead of a specific call by an average call handling time and divides the result
by an effective number af agents assigned to the queue.
4. The call routing system of claim 3 by the result.
5. The call routing system of claim 3 wherein one or more of the queues are virtual queues.
6. The call routing system of claim 3 wherein one or more of the queues are priority
queues wherein newly arrived calls may be inserted in the queue by priority ahead
of calls already in the queue.
7. A computer software application for determining an estimated call-waiting
time, comprising:
a function for determining the number of calls ahead of a designated call, and
multiplying that number by an estimated call-handling time, achieving a gross waiting
time; and
a function for dividing the gross waiting time by an effective number of agents
assigned to the queue.
8. The application of claim 7 comprising a function for abandoned calls by determining
a non-abandoned call rate and multiplying that by the estimated call waiting time.
Description
FIELD OF THE INVENTION
The present invention is in the field of Computer Telephony Integrated (CTI)
communication systems including both connection-oriented, switched telephony (COST)
systems and Data Network Telephony (DNT) systems such as Internet-Protocol-Network-Telephony
(IPNT) systems, and pertains more particularly to methods and apparatus for estimating
call waiting time for queues in skill-based agent level routing (ALR) environments.
BACKGROUND OF THE INVENTION
Telephone call processing and switching systems are, at the time of the
present patent application, relatively sophisticated, computerized systems, and
development and introduction of new systems continues. Much information on the
nature of such hardware and software is available in a number of publications accessible
to the present inventors and to those with skill in the art in general. For this
reason, much minute detail of known systems is not reproduced here, as to do so
may tend to obscure the facts of the invention.
At the time of filing the present patent application there continues to be remarkable
growth in telephone-based information systems. Recently emerging examples are telemarketing
operations and technical support operations, among many others, which have grown
apace with development and marketing of, for example, sophisticated computer equipment.
More traditional are systems for serving customers of large enterprises, such as
insurance companies and the like. In some cases enterprises develop and maintain
their own telephony operations with purchased or leased equipment, and in many
other cases, companies outsource such operations to firms that specialize in such services.
In a call center, a relatively large number of agents handle telephone communication
with callers. Each agent is typically assigned to a telephone connected to a central
switch, such as a PBX, which is in turn connected to a public-switched telephone
network (PSTN), well-known in the art. The central switch may be one of several
known types.
An organization having one or more call centers for serving customers typically
provides one or more telephone numbers to the public or to their customer base,
or both, that may be used to reach the service. These numbers are frequently of
the no-charge-to-calling-party variety. The number or numbers may be published
on product packaging, in advertisements, in user manuals, in computerized help
files, and the like. There are basically two scenarios. If the organization providing
the service has a single call center, the number may be to the call center, and
all further routing to an agent will be at the call center. If there are several
call centers, the organization may provide several numbers, one for each call center,
and the customer may be expected to use the number for the closest center, or for
the center advertised to provide specifically the service he or she might need.
In many cases the number provided will connect the caller with a first Service
Control Point (SCP) which is adapted to pre-process incoming calls and forward
the calls to call centers.
Routing of calls, then, may be on several levels. Pre-routing may be done
at SCPs and further routing may be, and often is, accomplished at individual call
centers. As described above, a call center typically involves a central switch,
typically including an Automatic Call Distributor (ACD). The central switch is
connected to the PSTN or other call network, as is well-known in the art. Agents,
trained to interact with callers, service telephones connected to the central switch.
If the call center consists of just a central switch and connected telephone
stations,
the routing that can be done is quite limited. Current art telephony switches,
although increasingly computerized, are limited in the range of computer processes
that may be performed. For this reason additional computer capability in the art
has been added for such central switches by connecting computer processors, adapted
to run control routines and to access databases, to the central switch. The processes
of incorporating computer enhancement to telephone switches is known in the art
as Computer Telephony Integration (CTI), and the hardware and software together
is referred to as CTI equipment. Typically the CTI processor, executing CTI applications,
monitors the activity of the switch and status of calls and equipment, and issues
instructions and commands to the switch.
In a CTI system, telephone stations having telephones connected to the central
switch may be equipped also with computer terminals, so agents manning such stations
may have access to stored data as well as being linked to incoming callers by a
telephone connection. Such stations may be interconnected in a local area network
(LAN) by any one of several known network protocols, with one or more servers also
connected to the network, and the CTI processor connected on the network as well.
When a call arrives at a call center, whether or no the call has been pre-processed
at a SCP, typically at least the telephone number of the calling line is made available
to the receiving switch at the call center by a telephone carrier. This service
is available by most PSTNs as caller-ID information in a format such as the well-known
ANIS system (Automatic Number Identification System). If the call center is computer-enhanced
(CTI), the phone number of the calling party may be used to access additional information
from a database at a server on the network that connects the agent workstations.
In this manner information pertinent to a call may be provided to an agent.
Even with present levels of CTI there are still problems in operating such call
centers, or a system of such call centers. For example there are waiting queues
with which to contend, and long waits may be experienced by some callers, while
other agents may be available who could handle callers stuck in call-center queues.
This condition is usually more prevalent in a large call-in center wherein a limited
number of agents must field many calls. It is generally desired that waiting periods
experienced by callers not be of such a length such that a caller becomes frustrated
and terminates the call. However, it is witnessed by many who patronize call centers
that much improvement is needed with regards to waiting time in call-center queues.
There are techniques practiced in the industry aimed at alleviating long caller-queue
waiting periods. One such standard development involves call load-balancing wherein
incoming calls are distributed (routed) more evenly to available call centers such
that queue lengths individual to separate call centers are somewhat the same. This
technique may also be practiced in single call centers wherein calls are distributed
among separate groups of agents. While this technique helps to even out call loads
among different queues, queue length may still be high during peak traffic periods.
Another technique involves transferring a call to an alternate destination
when that call approaches a pre-set maximum queue-waiting time for an agent. The
alternate destination may help to keep the caller on the line via interactive method
such as reviewing the purpose of the call or perhaps advertising products, while
waiting for an available agent. However, a long queue can still be an irritating
factor for many callers, even when some form of entertainment such as music is provided.
The above-described techniques may help to stabilize overall queue waiting times
within call centers, or help to alleviate caller stress when waiting time is excessive,
but they only partially address the problem. At peak call-in periods queue waits
may still be high even though calls are distributed evenly. Regardless of the distribution
(routing) method used, callers are generally not informed of expected waiting time.
Many callers who are not informed of an approximate waiting time will lose patience
and terminate the call after a short wait if they believe that they will have to
hold for much longer, even though in actuality, they may have terminated the call
just prior to being transferred to an agent.
One prior art system is taught in U.S. Pat. No. 5,020,095 entitled Interactive
Call Distribution Processor, filed on Nov. 16, 1988. This teaching provides a means
for informing a caller of a calculated (estimated) call-waiting time in a queue.
In this prior art system, however, the invention is limited in scope to an ACD
switching system utilizing a strict first-in-first-out (FIFO) queue. In this system,
a dedicated processor attatched to a standard ACD switch performs the required
calculating based on real-time performance related to call traffic including counting
previously queued calls ahead of a caller and estimating waiting time based on
an average of three calls against a pre-set time limit. If callers must be held
in queue beyond the pre-set limit, then they are asked to select another destination,
or they are disposed of by default.
While the above mentioned system technically provides for informing callers
of an estimated queue-waiting time, it is somewhat crude and limited in scope.
For example, in CTI telephony systems known to the present inventors, new skill-based
routing routines have been developed. As a consequence agents may be qualified
to participate in more than one queue. In other systems known to the present inventor,
queues are not rigidly structured, and incoming calls may be inserted by priority
ahead of calls already in a queue.
Advances in call routing using such as priority queues, virtual queues,
and the like, include routing to agents based on skill-set of the agent (e.g. language,
level of expertise, etc.), routing to agents based on level or state of availability,
routing to agents based on pre-acquired and/or pre-stored caller information, routing
to agents based on priority assignment of call, and so on. Rather, the queue is
stacked according to assigned call priority. Moreover, priority routing may also
be integrated with skill-based routing and other rules-based conventions.
In addition to priority queuing, virtual queues are also used in CTI enhanced
environments. A virtual queue is a method for tokenizing a call wherein the caller
may retain his position be it FIFO or priority queue after he has terminated the
call. When his position is the next "call" to be handled, an automated or manual
outbound dialer places a call to the original caller. When the caller answers,
he is connected to the available agent chosen to handle the call.
In the prior art there is not disclosed a flexible method for estimating queue
waiting times that could cover differing types of queues effectively. Moreover,
other factors that may effect estimated waiting time (EWT) such as abandoned calls,
redirected calls, error-routed calls, and the like are not considered or taken
into account.
It is desired that methods for estimating call waiting times in queue be much
refined so that such techniques may be practiced in vastly more complicated and
flexible environments such as those known to the inventor and described above.
Moreover, especially in CTI systems, there are further uses for estimated waiting
times beyond informing callers. Such estimates may be used in many machine decision-making processes.
What is clearly needed is a method for estimating call waiting times for various
types of queues including priority queues, virtual queues, and multiple-queue systems
wherein advanced intelligent routing routines are commonly practiced. Such a method
and apparatus would further improve enterprise-customer relations, and aid in increasing
enterprise profit, as well as enhancing efficiency and accuracy in many CTI functions.
SUMMARY OF THE INVENTION
In a preferred embodiment of the present invention a method for estimating, by
a processor coupled to a call waiting queue, waiting time for a designated call
in the call-waiting queue, wherein a plurality of agents handle calls in multiple
queues is provided, comprising steps of (a) determining the number of calls ahead
of the designated call; (b) determining the historical average call handling time
T(h) for calls in the queue; (c) for each agent handling calls in the queue determining
the portion of the agent's time devoted to the queue; (d) determining an effective
number of agents devoted to the queue by summing the time portions over all of
the agents; and (e) multiplying the number of calls ahead from step (a) by the
historical call handling time from step (b), and dividing the result by the effective
number of agents determined in step (d).
In an alternative embodiment the method accounts for abandoned calls by additional
steps of (f) determining an abandoned call rate; (g) determining not-abandoned
call rate by subtracting the abandoned call rate from integer 1; and (h) multiplying
the result of step (e) by the result of step (g).
In another aspect of the invention a call routing system is provided, comprising
a switching apparatus for switching calls to a plurality of agent stations; a computer-telephony
integration (CTI) processor coupled to the switching apparatus and adapted to maintain
multiple routing queues by a plurality of enterprise rules, wherein agents are
assigned to multiple queues, and an estimating application executing on the CTI
processor and adapted for determining an estimated waiting time for a selected
call in a selected queue. In this system the estimating application multiplies
the number of calls ahead of the selected call in the selected queue by an historical
average call handling time for calls in the queue, and divides the result by an
effective number of agents devoted to the queue determined by summing, over all
agents serving the queue either full or part time, the portions of each agents
time devoted to the selected queue. In a further embodiment the system further
accounts for abandoned calls by determining a non-abandoned call rate from an abandoned
call rate and multiplying the estimated call waiting time determined in claim 3
by the result. One or more of the call waiting queues may be virtual queues or
priority queues wherein newly arrived calls may be inserted in the queue by priority
ahead of calls already in the queue.
In yet another aspect the invention assumes the form of a computer telephony
integration
(CTI) software application, comprising a counting function for determining the
number of calls ahead of a designated call; a function for determining the historical
average call handling time T(h) for calls waiting in the queue; a calculation function
for retrieving the portion of time each agent assigned to the queue spends in tending
to calls in the queue; a summation function for determining an effective number
of agents devoted to the queue by summing the time portions over all of the agents;
and a calculation function for determining the estimated waiting time by multiplying
the number of calls ahead from the counting function by the historical call handling
time, and dividing the result by the effective number of agents from the summation
function. In this software there may be also a function for accounting for abandoned
calls by determining a non-abandoned call rate from an abandoned call rate and
multiplying the estimated call waiting time previously determined by the result.
With the innovations taught in the following disclosure in enabling detail,
for the first time, a function and apparatus for estimating waiting is provided
wherein users may reliably determine a close approximation of waiting time in sophisticated
call waiting queues for announcement to callers and for other purposes as well.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a block diagram illustrating a communication system having call-waiting
estimation capability according to prior art.
FIG. 2 is an overview of a CTI-enhanced telecommunications system wherein estimated-waiting
time (EWT) may be practiced according to an embodiment of the present invention.
FIG. 3 is a table illustrating practice of the present invention in a skill-based
priority queue.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram illustrating a communication system
11 wherein
calculation of estimated waiting time (EWT) is practiced according to the prior
art. As previously mentioned in the background section, prior art attempts to estimate
call waiting time in call-center queues is rather limited in scope. The prior art
approach cited in U.S. Pat. No. 5,020,095 assumes a limited hardware-fix that is
applicable only for an ACD system wherein strict FIFO queuing is practiced. To
further illustrate limitation in this approach, a prior art overview is illustrated below.
Communication system
11 comprises a PSTN
13 and a call-in
center
19. System
11 uses the well known ACD-type telephony switching
common to a COST network. For example, PSTN
13 has an ACD switch
15
connected therein and adapted to receive incoming calls represented by a vector
16 from anywhere in PSTN
13. ACD
15 is connected to an ACD
central switch
21 within call-in center
19 via telephony trunk
17.
ACD
21 is adapted as a central call-in switch and is a first destination
for all calls
16 destined to call-in center
19.
As is known in the art, ACD
21 employs a FIFO queuing system
22
wherein calls
16 wait until an available representative is available to
handle the call on a first-in first-out basis. ACD
21 is connected via an
internal wiring system
41 to a plurality of telephones
33,
35,
37, and
39 which are implemented one-telephone-per to agent workstations
25,
27,
29, and
31. Call-in center
19 is not
CTI enhanced to the extent that agents at workstations
25-
31 have
access to LAN connected PC's nor is call-in center
19 capable of much intelligent
routing such as is possible in CTI enhanced environments. It is to this simple
prior art system that EWT is implemented in rather limited scope as described above.
In order to achieve EWT in this prior art system, a call processor
23
is
provided as a dedicated unit for estimating waiting time associated with FIFO queue
22. Processor
23 is connected to ACD
21 via a data control
line
26. In prior art specification U.S. Pat. No. 5,020,095 which was mentioned
above with reference to the background section, incoming trunks
17 are diverted
through such a processor as processor
23 lending to the dedicated nature
of the device as disclosed therein. However, it will be apparent to one with skill
in the art that the same level of control over ACD
21 may be provided via
control line
26 with the appropriate trunk interfaces installed in ACD
21.
Processor
23 would not be considered a CTI processor in current art as intelligent
routing applications are not incorporated therein.
Several EWT software routines are provided and installed in processor
23
and adapted, among other purposes, for monitoring and interfacing with calls
16
as they arrive in queue
22. Other capabilities include agent monitoring
for busy or not busy, voice interface capability for informing callers of EWT,
a means for calculating average call time per call, a means for counting calls
ahead in queue
22, and a means for estimating EWT based on real-time averages
obtained from most recent call-length statistics. Optional facilities (not shown)
that may be connected to an ACD such as ACD
21 include a standard voice
messaging facility, and one or more live operator attendants.
In operation of prior art system
11, incoming calls
16 arrive at
ACD
15 in network
13 and are distributed over incoming trunk
17
to ACD
21 where they are queued (
22) in the order that they arrive.
Calls
16 are treated according to a pre-set queue limit, wherein once reached,
a next caller is optionally informed via recorded message that the queue is full
and offered another destination. The alternate option is to simply disconnect the
call. Only if queue
22 is functioning below a pre-set limit is EWT practiced
wherein a caller my be optionally informed of an estimated waiting time via one
of a plurality of stored pre-recorded messages that is most closely associated
with the current estimate which is based on the average time of the prior three
completed calls.
The method and apparatus of this prior art example is inflexible with regards
to other states that may exist. For example, a simplistic mathematical formula
may be adopted to reflect this prior art example. The formula:
N is the total calls in queue
22, T
h is the average time handling
each call, and m is the total sum of agents handling calls from queue
22.
This formula, which can be considered a basic formula, would apply in this example.
One limitation with this formula, as it applies to this case, is that it does not
consider abandoned calls, unless such abandoned calls are figured in abandoned
cal time, which is seldom the case A time estimate over three prior calls may include
one or more abandoned calls thereby producing an unnaturally low average call-handling
time that is communicated to the next caller arriving in queue. Moreover, EWT as
communicated to a caller must take into account the number of calls ahead of his
or her call in queue or N (total calls in queue). If there are many calls ahead
multiplied by an unnaturally low average call handling time, the caller may receive
a misleading time estimate.
Another problem with prior art as exemplified herein is that the actual time
for handling calls may vary widely from call to call. Therefore, taking an average
handling time over just a few calls (three in U.S. Pat. No. 5,020,095) is not reflective
of a confident average as it is well known that accuracy of any average taken improves
with the number of units (in this case calls) to be averaged. Still another state
that is not considered in the prior art is the fact that agents in many cases may
receive calls from more than one queue. Therefore, simply summing up the number
of agents (m) working from one queue will not suffice as a portion of their time
may be devoted to answering calls from another queue. Therefore, a more flexible
treatment of EWT must be accomplished by way of revised formulas and added software
in order to successfully and more accurately practice EWT. Such a flexible implementation
of EWT is described in enabling detail below.
FIG. 2 is an overview of a CTI-enhanced telecommunications system
45
wherein EWT may be practiced according to an embodiment of the present invention.
System
45 in this example comprises a PSTN network
47, an Internet
network
49, and a communication center
51. PSTN
47 may be
a public or private COST network as is known in the art. Internet
49 may
be of the form of another data-packet network as is known in the art such as a
private WAN or corporate Intranet. Communication center
51, in this embodiment,
is capable of receiving incoming calls from both PSTN
47 and Internet
49,
however, this is not required in order to practice the present invention.
A Service Control Point (SCP)
53, including a switching apparatus
56,
is provided in PSTN
47 and adapted to receive incoming calls represented
by vector
54 arriving from anywhere in PSTN
47. SCP
53 may
comprise any known type of telephony switch, including an ACD type switch. Also
illustrated within PSTN
47 and related to the SCP is a CTI processor
57
and a connected intelligent peripheral
61 of the form of an interactive
voice response (IVR) unit. IVR
61 is adapted to interface with callers on
incoming calls
54 in order to obtain additional information for routing purposes.
The purpose of SCP
53 at the network level is so that intelligent routing
may be performed in PSTN
47 before calls are in the domain of communication
center
51. For example, when a call
54 is intercepted by SCP
53,
IVR
61 may interact with the caller to obtain further detail regarding purpose
of the call, destination desired, level of skill required to service this caller,
and many other parameters such as may be asked a caller. A separate digital network
63 is provided and connects processor
57 to a processor
71
within communication center
51. In this way pertinate information about
a caller may be sent ahead of the actual call. In some cases only things like DNIS
and ANI are used.
SCP
53 is connected via a telephony trunk or trunks
55 to a central
telephony switch
69 within communication center
51. Actual incoming
calls are routed to switch
69 over trunk
55 while any information
obtained via IVR
61 (or otherwise) is transferred over digital network
63
to processor
71. Central switch
69 may be an ACD-type or other known
telephony switch. Processor
71 provides computer enhancement to switch
69
via CTI connection
73. Processor
71 may also provide enhancement
to switch
53 at the network level via digital network
63, processor
57, and CTI connection
59. This embodiment represents state-of-the-art
communication technology on the COST side of communication system
45 as
is known and available to the inventor.
Internet
49 is meant to illustrate, for purposes of discussion, that
the method and apparatus of the present invention may be adapted and equated to
data-network-telephony (DNT), and more particularly Internet-protocol-network-telephony
(IPNT) as would be practiced with regard to Internet
49 and communication
center
51 in this embodiment. However, for the purpose of this specification,
most reference will be to practice of the present invention in a COST network.
Within communication center
51, there is illustrated a plurality of
agent stations, station
79 and station
81. Stations
79 and
81 are each adapted and equipped to facilitate a communication center agent's
duties with regard to communication center
51. For example, station
79
has implemented therein a personal computer/video display unit (PC/VDU)
82
and an agent's telephone
83. Communication station
81 is likewise
equipped with a PC/VDU
84 and an agent's telephone
85. Agent's telephones
83, and
85 are connected to switch
69 via internal wiring
75 as is known in the art. There may be many more agent stations than the
two illustrated.
Communication stations
79 and
81 are interconnected via
their PC/VDU's to a LAN
77 for the purpose of obtaining and sharing information
through the course of normal communication-center operation. A customer information
system (CIS) server
87 is connected to LAN
77 and provides a source
of information regarding customers, products, services, and other like information.
Processor
71 also is LAN connected.
It will be apparent to one with skill in the art that there will be many more
communication stations such as station
79 operating in an actual communication
center of the type described herein. However, the inventor deems two such illustrated
stations and components therein sufficient for the purpose of adequately explaining
the present invention. It will also be apparent to one with skill in the art that
LAN connected PC/VDU's, such as PC/VDU
82 connected to LAN
77, are
not required in order to practice the present invention, but merely provide a state-of-the-art
example of implemented equipment that may be used in facilitating communication-center business.
Processor
71 has software
89 installed therein for accomplishing
methods of the present invention in a most flexible manner. For example, instances
of T-server and Stat-server (conventions known to the inventor) provide required
routing intelligence and statistical intelligence according to enterprise rules.
An instance of EWT software is, in a preferred embodiment, integrated with T-server
and Stat-server routines such that automated selection and execution of appropriate
routines may ensue in accordance with any prevailing enterprise rules including
number and type of queues used, specific routing routines, and so on. Software
89 may, in one embodiment, be provided as a single multifunction application.
Several queuing options
68 are provided and adapted to meet varying
needs according to the type of enterprise and business model preferred, or currently
practiced within communication center
51. As previously described with reference
to the background section, prior art is generally limited in application to a FIFO
type ACD queue. The software of the present invention (
89), however, may
be practiced with any type of queuing arrangement including the use of multiple
queues. In this way, an enterprise may be flexible in approach. For example, EWT's
may be calculated and communicated to callers and used for other purposes regardless
of what type of queue the calls are in, FIFO, Priority, Skill-based, Virtual, and
so on. It should be noted here that queues described wherein priority assignment,
skill-based routing, agent status routing, and so on are instituted are still technically
regarded as FIFO queues only in the sense that a progression is made with regards
to calls coming in to queue and calls being answered from queue. The ability to
stack queues and have calls advance according to various enterprise rules as disclosed
with reference to co-pending application Ser. No. 09/024,825 would, of course,
require more complex algorithms and statistical reporting in order to provide callers
with a reasonably accurate EWT. Such capability is not available in prior art systems.
In order to accomplish accurate EWT in an intelligent routing environment such
as system
45, the basic formula used for a simple FIFO ACD queue must be
expanded, and better statistical handling and reporting must be observed as described
above. In a preferred embodiment, statistical analysis and reporting of call behavior
is provided via Stat-server shown as part of software
89. Stat-server software
can be adapted to monitor and provide statistics regarding queues, switches, agent
status, call traffic, and so on. This method is vastly superior over prior art.
Statistical compilation capability may also be extended into PSTN
47 via
digital network
63 and processor
57. Similarly, EWT and T-server
capability may also be extended into PSTN
47 via the same conventions. In
this way EWT may be provided at network level queues associated with SCP
53.
More detail regarding expanded mathematical formulas and application thereof to
various queue situations for practicing EWT is provided below. Also hierarchical
systems can de assembled, where several call centers are connected to a network,
and controlled by a common SCP.
FIG. 3 shows a table
91 illustrating practice of the present invention
in a skill-based priority queue. Table
91 is intended to represent an exemplary
skill-based priority queue similar to one disclosed with reference to specification
Ser. No. 09/024,825 listed in the Cross-Reference to Related Documents section.
In table
91 there is a column
93 in which agent-skill levels are
listed. For example, English represents agents whose skill set is limited to the
fact that they speak English. Spanish represents agents whose skill set is limited
to the fact that they speak Spanish. Certified Trader/Eng. represents qualified
and licensed traders who speak English. Certified trader/SP. represents qualified
and licensed traders who speak Spanish.
Column
95 headed by title-block "# of Agents" represents the numbers
of individual agents working at the skill levels illustrated in column
93.
For example, there are 3 agents who are not certified traders who speak English
and are assigned to answering calls from the queue. There are 2 Spanish speaking
agents who are not certified traders answering calls from the queue. There are
3 certified traders who speak English and
1 certified trader who speaks
Spanish answering calls from the queue. In this exemplary embodiment, there are
a total of 9 agents assigned to answering calls from the queue. There is no duplication
in the "number of agents" column.
A column
97 lists average call handling times for agents in each skill
category
under title-block "Avg. Call". For example the 3 English speaking agents who are
not certified traders illustrated at the top left of table
91 have a combined
call-disposal-time (CDT) of 120 seconds. This means that a call answered by one
of these agents takes, on average, 120 seconds to dispose of from point of answer
to point of termination. Likewise, Spanish speaking agents are averaging 100 seconds
per call, certified traders speaking English are averaging 160 seconds per call,
and certified traders who speak Spanish are averaging 170 seconds per call.
The above CDT figures are real-time numbers based on statistical reporting provided
by Stat-server software as part of software
89 of FIG.
2. In a preferred
embodiment, CDT averages take into account the rate of abandoned calls occurring
within the queue and the amounts of time an agent may spend taking calls from another
queue if there is more than one queue. These factors are randomly occurring events
and are therefore impossible to account for when using the basic formula as described above.
An information table
105 lists some additional factors which can effect
an EWT determination for an incoming call. These are abandoned calls (described
above), bumped calls (priority queue), re-directed calls (error routed or transferred),
use of multiple queues, and use of virtual queues.
Calls are stacked in queue according to priority and skill requirement of a
caller. For example, in the column under title-block "Highest", the calls having
the highest priority are listed according to skill requirement. To the right, columns
labeled 2-7 and "lowest" reflect incremental lower levels of call priority with
actual calls waiting listed according to skill requirement. For example, the lowest
priority column has 5 calls listed and waiting for English speaking non-certified
agents. There are 7 calls ahead of the 5 lowest priority calls. These are 3 calls
in the fourth priority column, 2 calls in the third priority column, and 2 calls
in the highest priority column. In this embodiment, calls having a same priority
assignment in queue are answered according to FIFO rules, however a new call assigned
a higher priority would be placed ahead of any lower priority calls in queue and
behind any higher priority calls.
In this exemplary embodiment, a new call represented by vector
101 arrives
and is assigned 5
th priority in the queue and requires an English speaking
agent who does not have to be a certified trader. There are 7 calls ahead of call
101. Assuming then that another new call represented via a vector
103
arrives after call
101 and is assigned a 2
nd priority wherein
an English speaking non-certified agent is required, the number of calls ahead
with regards to call
101 increases by one. This assumes of course that all
3 English speaking agents are currently engaged with calls in the interim.
One with skill in the art may judge, from the preceding example, the difficulty
of providing a reasonably accurate EWT relative to call
101 as higher priority
calls may arrive and be placed in front in queue. Therefore, a periodic calculation
is performed and caller
101 is periodically informed via IVR of any further
delays, and perhaps given an option of increasing his priority or being transferred
to another agent or queue.
By taking the basic prior art formula reproduced again below we can modify for
different situations illustrated in information block
105 and described above.
To account for a multiple queue factor in basic FIFO queuing wherein agents only
spend a fraction of their time answering from any one queue, the basic formula
is modified as follows:
##EQU1##
In this notation, a fraction a
i represents the fraction of time an
agent spends answering calls from a single queue i. These fractions (may vary with
each agent) must be summed up over all of the agents answering calls from the queue.
This result represents the effective number of agents for the calculations used
as m in equation I.
When taking into account an abandoned call factor which is a random factor of
EWT itself, the above notation is multiplied by the percentage of calls that are
not expected to be abandoned as follows:
##EQU2##
In this equation, r
a is the rate of abandoned calls, so (1-r
a.)
is the rate of not-abandoned calls. This rate is computed as a dynamically self
adjusting factor which takes into account historical information on abandoned calls
obtained from Stat-server statistics. It will be apparent to one skilled in the
art of statistical calculation that the accuracy of this statistic will improve
as more information on call behavior becomes available. This is but one example
of how separate gathering of information by Stat-server software of software
89
of FIG. 2 is superior to prior art methods.
With the power of compiling statistical information concerning call behavior
such as CDT, rate of abandoned calls, rate of calls bumped, swapped or redirected
calls, and so on, a certain confidence level regarding the accuracy of these figures
may be developed through further calculation. These calculations are, in a preferred
embodiment, performed via EWT software in conjunction with Stat-server software
of software
89 of FIG.
2.
In some systems callers are informed of the EWT for their call on a periodic
basis
while waiting in queue. In the case of a simple FIFO queue wherein no priority
or other intelligent routines are employed, informing a caller of the EWT may be
performed once at the beginning of his wait. One will appreciate, however, that
in more complicated queue situations such as illustrated via table
91, wherein
priority routing and the like is performed, a caller will appreciate being informed
of any significant deviations of the original EWT as given at the beginning of
his wait.
Statistical information and calculated results will, of course, be more
accurate during peak periods when a high number of calls are being processed. Therefore,
the method of the present invention is more reliable during periods of greater
need. Callers during low-flow periods are usually handled expediently with much
less time waiting in a queue. In one embodiment, a call threshold may be established
in a queue so that callers waiting over a pre-set limit will be informed of an
EWT in queue while callers expected to be disposed of before the pre-set threshold
will not.
Taking a simple example such as provided herein with introduced call
101,
EWT for caller
101 will be 2+2+3 (calls in a higher priority)×120 seconds
(average CDT) divided by 3 (number of working agents). If caller
103 were
introduced immediately thereafter before agents dispose of their current calls,
then EWT for caller
101 would increase because of addition of call
103
which will be answered before call
101 because of priority. In this case,
call
101 is bumped via call
103.
In some embodiments virtual queues are composed as a product of varying routing
strategies employed within a communication center such as center
51 of FIG.
2. Virtual queues are often temporary, changing with differing routing routines
employed. In a virtual queue, a call is represented by a token and the caller may
hang-up and receive a call back when his or her call is next to be answered. More
description regarding a virtual queue is provided with regard to co-pending patent
application Ser. No. 09/024,825. The methods of the present invention may be employed
with virtual queues with a high degree of success as long as the designer of the
routing strategy provides meaningful objects from which statistics will be measured.
Because of the integrative nature of components of software
89 of FIG. 2
namely, EWT, Stat-server, and T-server implementations, new routing strategies
employing virtual queues may selectively obtain historical statistics related to
the behavior of specific types of calls that may be generic to the new strategy.
It will be apparent to one with skill in the art that the method and apparatus
of the present invention will work with any type of queue without departing from
the spirit and scope of the present invention such as with above mentioned types.
It will also be apparent to one with skill in the art that the present invention
may be practiced at network level at such switches that may be connected to a CTI
processor of the invention such as processor
57 of FIG.
2. Practice
of the present invention with respect to IPNT telephony is also possible and contemplated.
Therefore, the present invention should be afforded the broadest scope according
to the disclosure. The spirit and scope of the present invention is limited only
by the claims that follow.
*
