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UtilizationThe time that an agent is handling calls (talk time plus wrap-up time) divided by the total time that the agent is paid. It can be calculated by: net workload / gross workforce. Utilization = occupancy * productivity. Not to be confused with productivity or occupancy. | |
WorkloadThe amount of work on incoming call volume during a certain amount of time, usually measured in minutes. Can be measured without safety staffing (net workload) or with safety staffing (gross workload). Not to be confused with offered load. | |
WorkforceThe amount of available or required agent time when used in capacity calculations. Can be the net or gross workforce. Should match the workload. | |
SLService Level, a somewhat ambiguous term that in the broad sense can refer to all aspects of service (waiting time, abandonments, and so forth). In the narrow sense, it is defined as the percentage of calls answered within the AWT. The industry standard is 80/20: 80% of the calls have to be answered within 20 seconds. Quality of Service is a synonym of the former broader meaning. | |
Cost CenterFrom Wikipedia: ”In business, a cost centre is a division that adds to the cost of an organization, but only indirectly adds to its profit. Typical examples include Research and Development, Marketing and Customer service.” | |
AWTAcceptable Waiting Time, the target upper bound to the waiting time, often equal to 20 seconds, used in the definition of the SL. Also called Time to Answer (TTA) and Service Time (ST). | |
ASA | |
OccupancyThe time that an agent is handling calls (talk time plus wrap-up) divided by the total time that the agent is available for handling calls. It can be calculated by; net workload / gross workload or net workload / net workforce. Not to be confused with utilization or productivity. | |
Abandoned Call | |
FCFSFirst Come First Served, refers to the orders in which queued calls are served: in the order of arrival. | |
Traffic ManagementSynonym to RTPM. | |
MetricsQuantitative measures, commonly used for assessing, comparing, and tracking performance of a system. In contact center, a group of metrics is often displayed in a dashboard for analysis and decision supporting. For example, Handling time, Occupancy, Shrinkage, Longest Idle Agent, etc. | |
Intra-Day ManagementSee RTPM. | |
Call Center MathematicsAdvanced WFM calculations going beyond call center arithmetics, taking fluctuations and flexibility into account. | |
Call Center ArithmeticsBasic WFM calculations based on totals and averages, without taking fluctuations and flexibility into account. See also call center mathematics. | |
After Call WorkSee wrap-up time | |
SimulationThe activity of mimicking a real-world system over time, usually performed with a computer to evaluate the performance of such a system. | |
SeasonalityA forecasting term meaning that a pattern repeats itself, in call centers
typically at intra-day, intra-week and intra-year level. | |
Short AbandonA call that abandoned very quickly making it unlikely that the caller was already tired of waiting. | |
Quality of ServiceSee SL. | |
ProductivityThe time that an agent is available for handling calls divided by the total time that the agent is paid. It can be calculated by; gross workload / gross workforce, or net workforce / gross workforce. Not to be confused with utilization or occupancy. | |
PoissonFrench mathematician (1781-1840) who discovered the Poisson distribution which mathematically describes arrivals to a call center. Also used as Poisson process, focusing on the times of arrivals, and Poisson noise, focusing on the error with respect to the forecast. | |
PlanningThe organizational process of creating and maintaining a plan. | |
PatienceThe amount of time a customer is willing to wait before abandoning the queue. | |
Offered LoadSee load. | |
Net WorkloadThe amount of agent time needed to handle a certain amount of work, without accounting for safety staffing. For example, during a day, there are 1000 calls with an AHT of 4 minutes. Then the net workload is 4000 minutes. | |
Net WorkforceEqual to gross workload. | |
Load | |
Handling TimeThe time spent to handle a service request, which can be calculated over the following PABX metrics: Handling time = Ring time + Talk time + Hold time + Transfer time + Wrap-up time. See also AHT. | |
Gross WorkloadMeasure of the workload, which is equal to net workload plus safety staffing. Equal to net workforce. | |
Gross WorkforceMeasure of the workforce, which is equal to net workforce plus shrinkage. | |
Forecasting | |
Erlang-XA safety staffing model that, in addition to the Erlang C model, takes abandonments and retrials into account. | |
Erlang-CA safety staffing model that takes fluctuations in the number of arrivals and handling times into account. | |
ErlangDanish mathematician who created the safety staffing models. Also the dimensionless unit of load. | |
ChannelIn the context of contact centers, a means to have contact with customers. Examples are telephony, fax, and internet. | |
BPOBusiness process outsourcer, a company offering call center services, often to multiple organizations at the same time, regularly from a cheaper off-shored location such as India or the Philippines. | |
B2CBusiness-to-consumer, relative to commercial activities between business and end-consumers. | |
B2BBusiness-to-business, relative to commercial activities between businesses. | |
AHTAverage Handling Time, the time agents spend on average on a service request, usually a call, an email or a chat. The wrap-up time is also included. See also handling time. | |
AgentAn employee who works in a Call Center, also called (Call Center) representative ('rep'), or CSR (customers sales representative). | |
RedialThe fact that a caller, after having abandoned or being blocked, calls back after some time for the same service. See also abandonment. | |
Cross-trainedDenotes an agent who has more than one skill, who can therefore handle more than one type of call. A generalist is fully cross- trained. Also denoted as X-trained. | |
WFMWorkforce Management consists of all activities from forecasting and planning to online control that have to do with the employment of agents in call center. | |
Safety Staffing | |
ShrinkageThe fraction of paid time that an agent is not available for taking calls because of holidays, training, paid breaks, etc. Below you can see an example of a shrinkage table. It is important to note that this is merely an example to illustrate how shrinkage is calculated. There can be many more activities that can be added and not all activities are relevant for all companies. | |
Weighted MeanThe weighted mean is similar to the general mean, except that some points contribute more to the mean than some others. Mathematically if we have a set of points \(a_n\) and a set of weights \(w_n\) that belong to the points, then the weighted average is equal to \( WAV=\sum_{i=1}^{n}\frac{a_iw_i}{w_i} = \frac{a_1w_1 + a_2w_2 + \cdots + a_nw_n}{w_1+w_2+\cdots+w_n} \) for example, if we have two sets of points, 1 2 with weight 1 and 3 4 5 with weight 2, then the weighted average of all points is equal to \( \frac{1 \times 1+2 \times1+3 \times2+ 4 \times2+5 \times2}{1+1+2+2+2}=\frac{1+2+6+8+10}{1+1+2+2+2}=\frac{27}{8}=3.375 \) In excel there are two ways to calculate the weighted average. say we have the values in column A and the weights in column B. In the first method we set the product of A and B in column C. Then, the weighted average is given by WAV = SUM(C:C)/SUM(B:B) The second method uses the sumproduct function. This method doesn't require an additional column to be used. WAV = SUMPRODUCT(A:A,B:B)/SUM(B:B) | |
MeanThe mean (or average) of a series of numbers of length n is defined as the sum of the numbers in the series divided by n. In formula form this is shown as follows: \( AV = \frac{1}{n} \sum_{i=1}^{n} a_i = \frac{1}{n}(a_1+a_2+a_3+\cdots+a_n) \) For example: if our series of numbers is 1 2 3 4 5, then the mean is equal to \( \frac{1}{5} \times (1+2+3+4+5) = \frac{1}{5} \times 15 = 3 \). The excel function for the mean is AVERAGE() | |
TSLTelephone Service Factor, see SL. | |
SLAService Level Agreement, the contract between a business unit and higher management or an outsourcer with its client company concerning the required service levels. | |
SchedulingThe process of deciding how to commit resources between a variety of possible tasks. | |
RTPMReal-Time Performance Management, the activity having as goal on the day of execution to take actions as to obtain the required SL as good as possible. | |
Real-Time Performance ManagementSee RTPM | |
Order of OperationsWhen we speak about operations mathematically, it means things like add, subtract, multiply, divide, squaring, etc. Remember: If it isn't a number it is probably an operation.
7 + (6 × 52 + 3) ... what part should you calculate first? Start at the left and go to the right? Or go from right to left? Warning: Calculate them in the wrong order, and you will get a wrong answer ! So, long ago people agreed to follow rules when doing calculations, and they are:Do things in Parentheses First. Example:
source: mathisfun.com | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
IVR | |
GeneralistAn agent who has all skills and/or can handle all types of calls. | |
DNISDialed Number Identification Service, a part of the ACD that recognizes the calling number. | |
ANI | |
PABXPrivate Automatic Branch eXchange, the telephone switch local to the company. | |
Call Blending | |
CTIComputer-Telephony Integration, the process that enables communication between and integration of telephone equipment and computer systems. | |
X-trainedSynonym to cross-trained. | |
Wrap-up TimeTime after the end of a call that the agent spends on the call. Consist usually of entering call-related data in a computer system. | |
WFOWorkforce Optimization includes WFM, call monitoring and agent performance management. | |
WFM ToolA computer tool that assists planners with their WFM tasks. It minimally consists of forecasting, Erlang C, and agent scheduling modules. | |
Waiting Time | |
VRUVoice Response Unit, synonym to IVR. | |
TTATime To Answer, see AWT. | |
STService Time, see AWT. | |
SSFSingle skill first, an agent selection rule used in multi-skill call centers, that assigns calls to agents with the least number of skills. | |
SpecialistAn agent who can only handle one type of call. It can also mean an agent who can do even the most difficult calls, in contrast with a generalist. To avoid ambiguity it is better to use the term single-skilled agent. | |
Skill SetThe set of skills that an agent or group of agents have. | |
Skill GroupA group of agents all having the same skill set. | |
SBRSkill(s)-based routing, the fact that different types of calls are routed to different agent groups based on the type of the call and the skills of the agents. | |
RetrialThe fact that a caller, after having been served or not, calls back for the same service. Comprises of redials and reconnects. | |
ReconnectThe fact that a caller, after having been served, calls back after some time for the same service. See also FCR. | |
Predictive DialerFunctionality of an ACD that allows outbound calls to be automatically initiated, anticipating future availability of agents. | |
OROperations Research, the science that uses mathematical models to improve business operations. Also known as Management Science, therefore sometimes called OR/MS. See also www.informs.org. | |
NoiseInformal statistical term meaning unexplained variability (as in Poisson noise). | |
ModelUsed throughout the fellowship course as mathematical model, a description in mathematics terms of part of a system, that allows an analysis of certain aspects of that system. For example, a simulation model. | |
LWCLongest waiting call, a call selection rule used in multi-skill call centers. | |
LIALongest idle agent, an agent selection rule used in an ACD mechanism. The agent with the longest idle time since his/her last phone activity (after call work), will be offered the next call. | |
ICTInformation and Communication Technology, technology relative to computers and technology-assisted communication. | |
FCRFirst Call Resolution applies when a call is handled right the first time, not necessitating a second call. The FCR rate is the fraction of first calls for which this is the case. See also reconnect. | |
Data MiningA field of science aimed at discovering relations in data. It has a big overlap with statistics, but it is less mathematical, having its origins in computer science. | |
CRMCustomer Relationship Management, mainly used to denote computer systems that allow to record and retrieve interactions with the customer. CRM systems made the advent of call centers possible. | |
Contact CenterA collection of resources (typically agents and ICT equipment) capable of delivering services through multiple communication channels. | |
Call CenterA collection of resources (typically agents and ICT equipment) capable of delivering services by telephone. | |
AnalyticsAlso known as business analytics, a fact-based approach to business process and product improvement using advanced mathematics and ICT. | |
AlgorithmA step-by-step method to solve a certain, often computational, problem. | |
AE | |
ACDAutomatic Call Distributor, a part of a PABX that can distribute calls that arrive on one or more numbers to extensions which are part of one or more groups that are assigned to that number. | |