WFM Definitions
This WFM definition list guides you through the ever-changing world of workforce management, contact centers, and customer experience. It covers everything from basic abbreviations used by planners to the terminology experienced forecasters use. So the next time someone has a question about the difference between occupancy, productivity, and utilization, you are the one who can help!
We have strived to keep the WFM definitions as objective and complete as possible. However, definitions can be fluid and sometimes depend on context. If you have any questions or suggestions, please contact us, as we would be happy to discuss them with you. To reach the next-level and learn more about basic or advanced WFM, check out our (online) training and consultancy pages.
A
Abandoned Call
A call that the customer cancels before contact with an agent is made. Related to redial and abandonment.
Abandon Rate
Accessibility
ACD
Automatic Call Distributor, a part of a PABX (Private Automatic Branch eXchange) that can distribute calls that arrive on one or more numbers to extensions that are part of one or more groups that are assigned to that number.
ACW
After Call Work, time after the end of a call that the agent spends on the call. Consist usually of entering call-related data in a computer system. Also known as Wrap-up Time.
Adherence
Adherence is the level to which an agent adheres to their schedule. For example, if an agent is supposed to work an hour on inbound but starts 5 minutes late, then the adherence is 55/60=91.7%.
Not to be confused Conformance; the ratio between the hours worked and the hours planned. If you need to work 4 hours and actually work 6, the conformance is 6/4=150%.
AE
Average Excess, alternative service level definition, defined as the average time calls wait beyond the Acceptable Waiting Time (AWT).
After Call Work
Synonym of wrap-up time, the time after the end of a call that the agent spends on the call. Consist usually of entering call-related data in a computer system.
Agent
An employee who works in a Contact Center is also called a (Contact Center) representative (‘rep’) or CSR (Customer Service Representative).
Agent Group
AHT
Average Handling Time is the time agents spend on average on a service request, usually a call, an email, or a chat, including the wrap-up time. It is related to handling time.
Algorithm
A step-by-step method to solve a specific, often computational, problem.
Analytics
Also known as business analytics, a fact-based approach to business process and product improvement using advanced mathematics and ICT.
ANI
Automatic Number Identification is a technique used to identify customers by their telephone numbers. Used in combination with CTI (Computer-Telephony Integration) to show customer information immediately on the agent’s computer screen.
ASA
Average Speed of Answer is the average time a call waits before being connected to an agent.
Asynchronous channels
Asynchronous channels do not expect an immediate or real-time response. Customers and agents can engage in the conversation at their own pace (e.g. (e)mail or SMS). Also see synchronous channels.
Attrition
Attrition represents the loss of employees or staff, and it accounts for all employees that leave the company voluntarily (e.g., resignations) or involuntarily (e.g., terminations).
The attrition rate is the rate at which employees leave the company over a certain period. The attrition rate is a metric used in capacity planning to forecast the loss of staff and, consequently, the number of staff that would need replacing via new hires at a certain moment.
Available time
Average
See the definition of Mean.
AWT
Acceptable Waiting Time, the target upper bound to the waiting time, often equal to 20 seconds, is used in the Service Level (SL) definition. It is also called Time to Answer (TTA) and Service Time (ST).
B
B2B
Business-to-business, relative to commercial activities between businesses.
B2C
Business-to-consumer, relative to commercial activities between business and end-consumers.
Back-office
Blending
BPO
Business Process Outsourcer is a company that offers call center services, often to multiple organizations at the same time, regularly from a cheaper off-shored location such as India or the Philippines.
Business hours
C
Call Blending
A way of handling different call queues, for example, inbound and outbound calls, simultaneously by assigning them dynamically to one or multiple agent groups. Call blending is often implemented as a way of maximizing occupancy.
Call Center
A collection of resources (typically agents and ICT equipment) capable of delivering services by telephone.
Call Center Arithmetics
Basic WFM calculations based on totals and averages, without taking fluctuations and flexibility into account. Related to call center mathematics.
Capacity management
Capacity management describes the multitude of actions and strategies put in place to ensure optimized levels of staff against business demands (e.g., KPIs) at any given time; usually precedes schedule generation and accommodates for long-term planning of workforce staff, taking into account forecasted volumes, SLAs, shrinkage, budget constraints, etc.
Capacity plan
Call Center Mathematics
Advanced WFM calculations that go beyond call center arithmetics, taking fluctuations and flexibility into account. Related to call center arithmetics.
Caller ID
The caller ID is a number by which the caller can be uniquely identified. This could, for example, be a telephone or a customer number in case the caller is a member of the call center’s provided service. The caller ID finds an important use in the forecasting of the volume. By recognizing that the same customer called multiple times, it is possible to calculate the repeat traffic, allowing forecasting the fresh volume.
Channel
In the context of contact centers, a means to have contact with customers. Examples are telephony, fax, and the internet.
Conformance
Conformance is the ratio between the hours worked and the hours planned. If you need to work 4 hours and actually work 6, the conformance is 6/4=150%.
Not to be confused with Adherence; the level to which an agent adheres to their schedule. For example, if an agent is supposed to work an hour on inbound but starts 5 minutes late, then the adherence is 55/60=91.7%.
Contact Center
A collection of resources (typically agents and ICT equipment) capable of delivering services through multiple communication channels.
Cost Center
From Wikipedia: ”In business, a cost center 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.”
CRM
Customer Relationship Management is mainly used to denote computer systems that allow recording and retrieving interactions with the customer. CRM systems made the advent of call centers possible.
Cross-trained
Denotes an agent with more than one skill and thus can handle more than one type of call. A generalist is fully cross-trained. Also denoted as X-trained.
CSR
Customer Service Representative, an employee who works in a Contact Center. Is also called a (Contact Center) representative (‘rep’) or agent.
CTI
Computer-Telephony Integration is the process that enables the communication between and integration of telephone equipment and computer systems.
Customer Experience (CX)
Customer Experience refers to how customers perceive your organization, brand, or company as a result of their interactions. It can encompass the entire customer journey from the first contact with the company via advertising pre-purchase to the very last experience with customer care post-purchase. In a contact center or customer support department, WFM has a role in facilitating a positive experience for the customer with each agent-facing interaction by aiming to staff the right agents, with the right skills, at the right time.
Customer journey
The customer journey represents all interactions a client has with the business via all available channels; it most often describes an end-to-end experience of the customer, including feelings, behaviors, actions, and the steps or phases a customer has to go through throughout the customer lifecycle.
D
Data Mining
A field of science aimed at discovering relations in data. It significantly overlaps with statistics, but it is less mathematical, having origins in computer science.
Decimal Separator
The Decimal Separator is the character used to indicate where the fractional part of a number begins and where the integer part ends.
The symbol used for the decimal separator differs per country and is either a dot ‘.’ or a comma ‘,’. Because of this, the decimal separator also differs between versions of Excel.
Within CCmath, we use the English version of Excel. Therefore we use the dot as the decimal separator.
Demand Forecasting
DNIS
Dialed Number Identification Service, a part of the ACD (Automatic Call Distributor) that recognizes the calling number.
E
Employee Experience (EX)
Employee Experience (EX) includes all positive and negative interactions that people experience from the moment they are hired to the moment they leave the company. In a contact center, WFM can play a pivotal role in EX through advanced and optimized scheduling that fosters employee engagement and an overall positive employee experience. For example, WFM processes and tools can contribute to a positive EX through increased transparency and fair scheduling, autonomy through self-scheduling, satisfaction by working preferred shifts or according to availability, flexibility through shift swapping, etc.
Erlang
Erlang can refer to multiple things:
- A.K. Erlang (1878-1929), a Danish mathematician who invented the Erlang B and Erlang C models
- The (dimensionless) unit of load; the amount of work offered to the system, defined by the product of the forecast and the AHT.
- A programming language
- The safety staffing models named after A.K. Erlang
Erlang B
Erlang B is a safety staffing model invented by A.K. Erlang (1878-1929) without a queue, meaning that customers who do not find an available agent leave the system immediately. Mostly used in telecommunications and health care, less relevant to call centers.
Erlang C
A safety staffing model that considers fluctuations in the number of arrivals and handling times.
Erlang X
A safety staffing model that, in addition to the Erlang C model, takes abandonments and retrials into account.
Event
F
FCFS
First Come First Served refers to the orders in which queued calls are served: in the order of arrival.
FCR
First Call Resolution applies when a call is handled right the first time, not necessitating a second call. The FCR rate is the fraction of the first calls for which this is the case. Related to reconnect.
First-time resolution
The first-time resolution, also known as first-time fix or first-call resolution, is when a customer’s contact is handled successfully the first time they call, thereby preventing the need to make follow-up calls. An important key performance indicator is the FTR rate, defined as the total number of contacts resolved on the first try divided by the total number of contacts received.
Forecast Accuracy
Forecast accuracy describes how close a forecast is to the actuals it predicted. It is often used for the number of calls, but it can also be used for other quantities, such as the AHT (average handling time). There are different ways to measure it; the WAPE (weighted absolute percentage error) is prevalent.
Forecasting
The prediction of (exogenous) variables such as call volume, AHT (Average Handling Time), and patience.
FTE
FTE stands for full-time equivalent, a measurement that represents the total number of hours a full-time employee works. E.g., in a company, 1 FTE = 40 hours, then two employees, each working 20 hours, will account for 1 FTE.
G
Generalist
An agent with all skills and/or can handle all types of calls.
Gross Workforce
Measure of the workforce that is equal to the net workforce plus shrinkage.
Gross Workload
Measure of the workload, which is equal to the net workload plus safety staffing. Equal to the net workforce.
H
Handled Call
Handling Time
The time spent to handle a service request that can be calculated over the following PABX (Private Automatic Branch eXchange) metrics: Handling time = Ring time + Talk time + Hold time + Transfer time + Wrap-up time. Related to AHT (Average Handling Time).
Hold Time
Holt-Winters
Holt-Winters is a forecasting method, named after its inventors, based on the principles of exponential smoothing, which includes approximations of the long-term trend and the impact of one seasonal pattern.
I
ICT
Information and Communication Technology, technology relative to computers and technology-assisted communication.
Inbound
Inbound, as in inbound call, is the incoming call that is made by a customer to a call center or contact center.
Interval (Forecasting)
A forecasting interval is the minimal time unit to make a forecast. It is commonly set to 15 min, 30 min, or 1 hour depending on how fluctuating the forecast is. The forecast per interval will guide capacity planning or scheduling decisions. For instance, the number of call volumes that fall in each interval and the average handling time of that interval will decide the net workload.
Intra-Day Management
Synonym of Real-Time Performance Management, the activity has as the goal on the day of execution to take actions to obtain the required service level as well as possible.
K
KPI
L
LIA
Longest idle agent, an agent selection rule used in an ACD (Automatic Call Distributor) mechanism. The agent with the longest idle time since their last phone activity (after call work) will be offered the next call.
Load
Amount of work offered to the system, defined by the product of the forecast and the AHT (Average Handling Time), measured in Erlang. For example: if the forecast of the arrival rate is 4/min and the AHT is 3 minutes, then the load is 4 * 3 = 12 Erlang.
Load Balancing
Load balancing is distributing the workload among agents based on their skill sets and skill levels. This is often related to the routing rules used in call centers. A good routing rule should be able to distribute the workload to the right agent at the right moment so that the workload can be most effectively handled and balanced. Eventually, it will reduce the callers’ waiting time, increase agents’ productivity and occupancy and improve callers’ satisfaction and call center efficiency.
LWC
Longest Waiting Call, a call selection rule used in multi-skill call centers.
M
Mean
Mean often refers to the arithmetic mean, which is also known as average. When we have a series of numbers () of length n, the mean is defined as the sum of the numbers in this series divided by the length n. In formula form, this is shown as follows:
An example is as follows, a series of numbers (2,4,6,8,10) with length 5, the mean is equal to:
Metrics
Quantitative measures that are commonly used for assessing, comparing, and tracking the performance of a system. In a contact center, a group of metrics is often displayed in a dashboard for analysis and decision support. For example, Handling time, Occupancy, Shrinkage, Longest Idle Agent, etc.
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.
Multi-Channel
Similar to multi-skilled, multi-channel refers to the possibility of customers contacting the contact center via different channels. Different channels could, for instance, be phone, e-mail, chat, and social media.
Multi-Skilled
A contact center is said to be multi-skilled when the contact center offers multiple types of contacts, e.g., different kinds of products or languages. Each other type of contact is called a skill. An agent is said to be multi-skilled if the agent is capable of handling more than one skill.
N
Net Workforce
Equal to gross workload.
Net Workload
The amount of agent time needed to handle a certain amount of work without accounting for safety staffing. For example, if there are 1000 calls with an AHT of 4 minutes during the day, then the net workload is 4000 minutes.
Noise
Informal statistical term meaning unexplained variability (as in Poisson noise).
Non-productive hours
The portion of contract hours that is not spent handling customer contact. With that, it is the equivalent of all scheduled time minus total handling time and available time.
Net Promoter Score (NPS)
O
Occupancy
The time that an agent handles calls (talk time plus wrap-up) is 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.
Offered load
Amount of work offered to the system, defined by the product of the forecast and the AHT (Average Handling Time), measured in Erlang. For example: if the forecast of the arrival rate is 4/min and the AHT is 3 minutes, then the load is 4 * 3 = 12 Erlang.
OR
Operations Research is the science that uses mathematical models to improve business operations. Also known as Management Science, therefore sometimes called OR/MS. See also Informs.org.
Order of Operations
The order of operations is the rule that tells us in which order a mathematical expression should be evaluated. This is especially important when dealing with an expression with multiple different operations. Operations are things like adding (+), subtracting (-), multiplying (*), or dividing (/). The correct order follows the PEMDAS principle:
- P: Everything between parentheses should be evaluated first.
- E: Work out exponents next.
- MD: Multiplication and division are evaluated from left to right, whichever comes first.
- AS: Addition and subtraction are finally evaluated from left to right as well.
Outbound
Outbound, as in an outbound call, is a call initiated by a contact center agent. Outbound calls are typically made to prospective customers and focus on sales, lead generation, telemarketing, and fundraising.
Outsourcing
Outsourcing is the practice of hiring an external company to deliver services. In the context of contact centers, such a company is called a Business Process Outsourcer, which is thus a company providing call center services such as handling all calls for a client company.
Overstaffing
P
PABX
Private Automatic Branch eXchange (PABX or PBX) is a telephone exchange used privately by a company.
Patience
The amount of time a customer is willing to wait before abandoning the queue.
Planning
The organizational process of creating and maintaining a plan.
Poisson
French mathematician (1781-1840) discovered the Poisson distribution, which mathematically describes arrivals to a call center. Also used as the Poisson process, focusing on the times of arrivals, and Poisson noise, focusing on the error with respect to the forecast.
Predictive Dialer
The functionality of an ACD (Automatic Call Distributor) that allows outbound calls to be automatically initiated, anticipating the future availability of agents.
Productivity
The time an agent is available to handle calls is divided by the total time 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.
Q
Quality of Service
A synonym of Service Level, is 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 (Acceptable Waiting Time). The industry standard is 80/20: 80% of calls must be answered within 20 seconds. Quality of Service is a synonym of the former broader meaning.
Queue / Call Queue
A queue in contact centers is where calling customers are placed on hold in a virtual waiting line, waiting for their turn to be answered by an employee. For example, customers waiting for an available employee at a bank counter similarly wait in a queue.
R
Reachability
Reconnect
The fact that a caller, after having been served, calls back after some time for the same service. Related to FCR (First Call Resolution).
Redial
After being abandoned or blocked, a caller calls back after some time for the same service. Related to abandonment and abandoned call.
Retrial
A caller, after being served or not, calls back for the same service. Comprises of redials and reconnects.
Routing
Routing in contact centers is the process of directing customer requests (calls, chats, etc.) to the most appropriate department/team/agent group. It is an integral part of any contact center’s customer service strategy. Routing can be done manually or through automated systems such as Interactive Voice Response (IVR). Automated routing often uses pre-defined criteria such as customer type, language, and geographic location to determine the best customer service option. Please also see Skill-Based Routing (SBR).
Real-Time Performance Management (RTPM)
Synonym of Intra-Day Management, the activity has as the goal on the day of execution to take actions to obtain the required service level as well as possible.
S
Safety Staffing
The additional number of agents needed to reach a certain service level. The safety staffing level is often calculated utilizing the Erlang C or Erlang X formulas.
SBR
Skill(s)-Based Routing, different types of calls are routed to different agent groups based on the type of the call and the agents’ skills.
Scenario
Scenario, in general, means a possible course of events. In the context of contact centers, scenarios are used in the context of forecasting and predicting service levels, where scenarios are differentiated based on underlying parameters. E.g., different forecasting scenarios could be made under different assumptions on the future sales of a company’s products.
Scheduling
The process of deciding how to commit resources between various possible tasks.
Scheduling Rule
Scheduling rules are made to help assign qualified shifts to agents. There are different types of scheduling rules, such as agents’ unavailability, the minimum rest time between two consecutive shifts, the time window to schedule breaks, and so on. Some rules are made to follow labor laws and business requirements. At the same time, rules can also be made to achieve better service levels or to keep fairness among agents to consider agents’ preferences.
Seasonality
A forecasting term that means a pattern repeats itself in call centers typically at intra-day, intra-week, and intra-year levels.
Self-scheduling
As the name implies, it is the practice of letting team members choose the shifts they want to work — or trade shifts with others — to create the most optimal schedule for themselves and their coworkers. The manager still exercises a modicum of control over the process, including configuring the needs and constraints.
Self-service
Self-service is a channel that allows customers to change specific agreements or settings themselves, such as choosing a new type of phone subscription. This can be done via a website, chatbot, personal environment, or voice self-service (e.g., buying stocks).
Self-service is essential to recognize as a channel, meaning that a number of customers will use this channel to organize their subscriptions, ask questions, get answers, etc. It can be forecasted as a regular channel and is essential since changes in the self-service platform or (temporal) failure of the platform can result in higher volumes or longer AHTs on other channels.
Typically self-service has no AHT attached, only volumes. Volume recognition can be specified either as customers logging into their personal environment and starting or ending an action, combined with the number of people visiting a company website that gets an answer to their question.
Shift
A shift is a set amount of time an employer schedules and expects an employee to work. It consists of a start time and an end time within which various activities take place: handling time, available time, break(s), and any other time not primarily devoted to handling time or available time. Think of sick leave, training, consultation, etc.
Shift Bidding
Shift bidding is a process whereby one or more employees can express interest in working an open shift. It is an automated alternative method to scheduling that allows the scheduler to retain total control while giving employees more autonomy over their schedule.
Shift Swapping
The shift swap is an easy way to ensure that shifts and/or parts of shifts can be exchanged between employees. Employees negotiate the hours and agree to swap their shifts without bothering anyone about their plans. Approval or denial can be automated by the system based on configured constraints.
Short Abandon
A call that was abandoned very quickly made it unlikely that the caller was already tired of waiting.
Shrinkage
The fraction of paid time that an agent is not available to take 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 of how shrinkage is calculated. Many more activities can be added, and not all activities are relevant for all companies.
Simulation
The activity of mimicking a real-world system over time is usually performed with a computer to evaluate the performance of such a system.
Skill Group
A group of agents all having the same skill set.
Skill Set
The set of skills that an agent or group of agents have.
SL
Service Level is 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 (Acceptable Waiting Time). The industry standard is 80/20: 80% of calls must be answered within 20 seconds. Quality of Service is a synonym of the former broader meaning.
SLA
Service Level Agreement, is the contract between a business unit and higher management or an outsourcer with its client company concerning the required service levels.
Specialist
An agent who can only handle one type of call. It can also mean an agent who can do even the most difficult calls, contrasting with a generalist. To avoid ambiguity, it is better to use the term single-skilled agent.
(Smoothing) Spline method
Smoothing splines are a statistical method to draw a smooth line that is simultaneously close to a number of points. In call centers, it can create smooth intra-day patterns, avoiding the spiked overfitted patterns that result from averaging. In our white paper ‘More precision with less data: a new approach to intra-day patterns,’ you can learn more about splines.
SSF
Single Skill First, an agent selection rule is used in multi-skill call centers that assigns calls to agents with the least number of skills.
ST
Service Time, the target upper bound to the waiting time, often equal to 20 seconds, is used in the service level definition. It is also called Time to Answer (TTA) and Service Time (ST).
Synchronous channels
Synchronous channels support immediate, real-time interactions between a customer and an agent (e.g., phone, live chat, instant messaging). Also see asynchronous channels.
T
Trend
Trend, in the context of forecasting, is the long-term tendency of forecasted numbers. Not to be confused with seasonality, which is a recurring pattern.
TSL
Telephone Service Factor, related to Service level (SL).
TTA
Time To Answer, related to Acceptable Waiting Time (AWT).
U
Understaffing
Utilization
The total time that an agent is handling contacts (including wrap-up time) plus the time that the agent is available for handling contacts, divided by the total time that the agent is paid. It can be calculated by: net workload plus availability / gross workforce. Not to be confused with Productivity or Occupancy.
V
Volume
VRU
Voice Response Unit is part of an ACD (Automatic Call Distributor) that allows customers to enter information by responding to instructions through the telephone’s keypad or the VRU.
W
Waiting Time
The time a call spends between entering the queue (often after a recorded message or after having been chosen by a Voice Response Unit) and an agent is connected to the call.
Weighted Mean
The weighted mean is similar to the Mean (arithmetic mean), except that each data point in a series contributes equally to the final average in arithmetic mean. But in weighted mean, some data points can contribute more than others. The contribution of each data point is quantified by weight.
When we have a series of numbers () of length n, and the corresponding weights are (), then the weighted mean is defined as the sum of the multiplication between each number and its weight in this series divided by the sum of all weights. In formula form, this is shown as follows:
An example is as follows, a series of numbers (2,4,6,8,10) with a length of 5, and the weight of each number is (1, 1, 1, 1, 2). The weighted mean is equal to:
Note that the arithmetic mean is equal to the weighted mean when all the data point has the same weight:
A series of numbers is (2,4,6,8,10) with a length of 5, and the weight of each number is (1, 1, 1, 1, 1). The weighted mean is equal to:
This is equal to:
Weighted Moving Average
The weighted moving average is a forecasting method. Similar to the Simple Moving Average method, it takes the average of the historical data of a fixed length every time, making a forecast. However, the weighted moving average gives more weight to recent data than past data. Therefore, the forecast will follow the trend more closely.
WFM
Workforce Management consists of all activities from forecasting and planning to online control, thus everything that has to do with the employment of agents in a contact center.
WFM Tool
A computer tool that assists planners with their WFM tasks. It minimally consists of forecasting, Erlang C, and agent scheduling modules.
WFO
Workforce Optimization includes WFM, call monitoring, and agent performance management.
Workforce
The amount of available or required agent time when used in capacity calculations. It can be the net or gross workforce and should match the workload.
Workload
The amount of work on incoming call volume during a certain amount of time is usually measured in minutes. It can be measured without safety staffing (net workload) or with safety staffing (gross workload). Not to be confused with the offered load.
Wrap-up Time
Time after the end of a call that the agent spends on the call. Consist usually of entering call-related data in a computer system. Also known as After Call Work (ACW).
X
X-trained
Abriavation of Cross-trained. Denotes an agent with more than one skill and can thus handle more than one type of call. A generalist is fully cross-trained.