Top Tips on How To Define and Measure Service Level in Call Centers

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Looking at the big picture and asking hard questions about the call center service level is the first step to success. Strategic thinking, bridging the service level with the needs of customers ensures lasting revenue and strong relationships. Building an on-demand call center to meet both company and customer needs is easy when you have a strategy.

Service level targets are in resolving maximum issues in a minimum time before they escalate. These days, software for call centers gives versatile options to reduce strain from live agents by using IVR, robocalls, and chatbot functions.

A-class call center performance is delivering value to customers across all channels, 24 hours a day, even in hours outside of work. There are three main service-level models you can work with: standard, relaxed, and boosted.

Source: CallCentreHelper

Let’s find out how satisfaction level and ongoing value depend on service level models.

Standard model

The 80-20 service level means answering 80% of incoming calls within 20 seconds from the start of a phone ringing. It's valuable for customers to achieve a solution as fast as possible, and 80/20 guarantees adequate workflow and standard queue time for customers.

This is the main industry standard, which most call centers over the globe apply as a basis. The advantage of the model is delivering a decent level of customer experience without wasting additional budget. Agents keep energized and motivated during the day due to the adequate workload and scheduled agent break times.

It also prevents the burning out agents due to the high calling volume. The model allows you to deliver service economically and proactively.  

This is a model that small or mid-sized businesses need to consider from the start of their business. Then when they achieve practical knowledge, ROI, experience, and positive service level metric, they could move to other models, such as relaxed or boosted. 

Service level over omnichannel sources communication in a standard model looks like this:

  • Phone. Answering 80% of phone calls within 20 seconds;
  • Chats. Answering 80% of messages within 20 seconds;
  • SMS. Answering 80% of SMS within 20 seconds;
  • Emails. Answering 100% emails within 24 hours;
  • Social media. Answering 100% of social media messages within 60 minutes or 4 hours;
  • Business letters. Answering 95% of letters within 3 business days.

The reason why emails and social media have more room for answering is that the number of requests through these sources of communication is drastically low. However, it's better to set KPI metrics and track incoming requests to change on-demand tactics.

Relaxed model

This is the model when you give a wider time room for your agents to meet service level objectives. As an example, you have a window with a model like 75/20 or 80/30. That means you process 75% of incoming requests within 20 seconds and 80% within 30 seconds, accordingly.

Your agents will have more time before picking up the phone and have more time for conversation. The model works perfectly when you have an understaffed call center or less competitive markets in which the necessity for quick answering is diminished. 

Boosted model

Frankly, boosted models like 80/15 or 90(95)/10 means your agents answer 80%, 90%, or 95% of calls and messages, within 15 or 10 seconds accordingly. It creates less time intervals and tighter environments for answering through omnichannel sources.

The boosted model gives you a vehicle to increase customer experience and satisfaction. Allows you to make more sales and occupy more inquiries. The benefit of this model is irresistible in terms that customers will likely have relationships with the company that solves their problems as fast as possible.

Boosted model more natural for top-tier contact centers and experienced agents with expertise in tackling requests with quality and speed.

However, to successfully launch this model on a long-running basis, you need more qualified agents in a call center at a time, and perhaps a new approach to agent shifts. It’s important to prevent the overwhelming and burnout of your agents that start to make mistakes or mislead customers.

These three models represent an overall idea of how call centers use their billable time, workload, and answering habits. Answering habits through phone, chat, SMS, social media, email, and letters may vary. It depends on the goals, staffing model, and corporate policy.

Futuristic model

It's challenging to meet adequate call center service level agreement with a model like 100/20. It requires an additional budget, experienced agents, and working time. Add to these requirements technical and human factors, and see a big picture of this work.

From the business perspective, it's hard and unprofitable to keep the excess number of agents in a call center. They have to constantly be available on all sources of communication such as phone, chat, email, and social media.

However, this could be the case when you need to tackle a high calling volume on a particular day, like a time of marketing campaign with an expected calling volume. In this case, you’ll need to furnish a call center with an exceeding number of agents, organize challenging assignments and develop flexible shifts.

Yet in a long-term perspective, it’s inevitably going to lower your service, because of numerous circumstances like human factors or technical problems both from the company and the customer.

Which model do you need to choose to meet all your needs in a call center?

Your market and the competition are the answers to these questions. The more competitive your market, the more necessity towards the boosted model. The highest percentage of calls answered should be in competitive markets such as health care, agriculture, exchange markets, banking, food, e-commerce, and real estate. The cost of this call center is high, yet revenues from each deal are tremendous.

Less competitive markets are sports equipment, office furniture, pet products, solar energy, etc. These markets give you a wide room to use a relaxed model of your call center. Maintaining this call center will carry predictable expenses, while operational efficiency will be profitable.

How many agents do you need in a call center?

The number of qualified agents in your call center depends on budget, the competitiveness of markets, business goals, and expected revenues. Set a budget and discuss with stakeholders the issue of how much you need agents in a call center to meet all your needs.

The cost-effectiveness of call centers stems from staff workload and successful call resolutions. The number of agents in a call center doesn’t guarantee a 5-star customer experience.

Staff's impact on service level

The work of a call center is critical for delivering important information to customers at exact times. When you struggle with staff problems, you need to fire or hire agents. After all these internal adjustments influence service level, employee satisfaction, work, brand image, and ROI.

These days hiring qualified agents is challenging. Hiring the right amount of qualified agents is crucial for your call center, and there are some pros and cons you should know.

First of all, hire the right agents in your call center work. There are always people that want to work in your call center. During the hiring process, you need to look at such qualities as language, professionalism, enthusiasm, and passion. 

Prevent hiring the first person that wants to get a job from you. Despite the rich pool of agents for hire over the globe, you need to have a proven method of hiring that guarantees the maintenance and lasting productivity of agents. Test this person and define how it will be appropriate for you. Give them a test assignment, and look at how they will tackle it. 

Decide whether you hire a particular person or not within 48 hours. Then, after a few weeks, decide whether you want to see this person in your team or not. By doing so, you’ll ensure working in your team with highly competitive personalities and eliminating those who are not qualified.

Hiring the right person is the first step in increasing service level, saving more money, and achieving ongoing revenue growth. The competitiveness of the right person will grow with the company, and the revenue per agent will grow. 

Soon you’ll find out that the right individuals generate 3x times more service level and ROI than the average agent. When you fire an agent that works with you for some time, you create a short-period weakness for your call center. Someone has to do more work in this case, and it's lowering the efficiency of that person. As a result, maintaining a qualified agent is drastically more cost-effective than the periodical hiring of a new one.

Cultural differences involve the performance of agents. When you hire agents for a particular goal or campaign, you need to consider their culture and how it impacts sales, customer experience, and customer satisfaction scores. 

The hiring of agents in a country where a customer is located increases the chances for an astonishing customer experience. 

Define and promote leaders in call centers

Every call center needs a leader that tackles the most challenging assignments and helps other agents to face their challenges. 

The role of head agent is valuable when there is a call from a VIP account or a challenging assignment that nobody in a call center is qualified to tackle. While less experienced agents waste time trying to find a solution, leaders do it in an easy and professional fashion.

The role of leaders is to ensure the adequate workload and performance of every agent. The decision about promoting or firing a particular person should be also in the competence of leaders of call centers.

Maintain control over your call center

Also, you put the right people in their places, hired, promoted, and organized your work, as a head of a call center needs to maintain control over your call center. You need to track the activity of all agents of your call centers, from newbies to leaders. 

Making a decision on hiring, promoting, and firing agents, you need to take into account the opinions of qualified agents, yet it’s up to you to make key decisions about the call center’s staff and activities.

Heads of the call center need to maintain control over a call center's agent to understand the way agents work and adjust new strategies, training sessions, and corporate policy.


Agents in different time zones work in particular hours most of the time. If you have a goal you schedule the work of agents to meet your needs.

To increase the productivity of your staff, ideally, you need to define shifts for your agents. There are a few shifts, that your agents:

  • Standard shifts. You agree with agents about the schedule and the exact hours of work per day. This is the most common type of shift, so your agents know when they work and how much they earn.
  • Part-time. It’s not quite good to have a part-time worker, yet when you have a necessity for additional agents, you can use this type of shift. Agents work a certain amount of hours per day or week and help you to meet the call center’s goals;
  • Split-time. When your agents work for periods of time during the day. This shift is relevant when you have a pick of calling volume during the day. You can use it as an advantage for agents and schedule work in these peaks.

Make service level calculations during a week to define actual and real service levels.

Firstly, all call centers have different workload during the week. The highest calling picks for call centers over the globe are expected on Monday, Tuesday, and Wednesday. 

On Thursday, Friday, Saturday, Sunday, the calling volume will be reduced day by day. Saturday and Sunday are the most relaxed days of the week.

It’s important to notice that the higher the calling volume the lower the service level in a call center due to request’s pressure. 

When a call center’s calling pressure reduces in four days after Wednesday, your service level will be on the rise.

Taking into account these factors, it’s easy to calculate percentages of weighted volume, service level, and weighted service level. Take a look at these charts to understand the idea.

Day of a week

Actual Service Level

Calling volume

























We can calculate the Actual service level during a week by this call center service level formula:

Now, let’s calculate the weighted volume and weighted service level to define a real percentage of workload. The weighted volume is calculated by the formula:

For a Monday Average Service Level = 4,390/20,535 * 100% = 21.4%.

To calculate Weighted Service Level for a call center, we need to use this formula:

Day of a week

Weighted Volume

Service Level

Weighted Service Level






























Finally, to find out a real service level during a week, we need to sum the weighted service level one by one: 11.1+13.1+13.3+13.3+9.1+8.2+3.7 = 71.8%. 

Now we have a more accurate calculation of service level in a call center. From these calculations, we see that the difference between the formula of defining actual service level 78% and real service level during a week – 71.8% is different. The difference – is 6.2%

The ways to reduce strain for agents and increase service level

Advanced software for call centers gives a wide pool of options to reduce strain from agents. Automatic call distribution (ACD) and interactive voice response system (IVR) positively impact a call center.

Resolving issues within one touchpoint is crucial, and routing customers to the most relevant agent or department has supreme value. ACD works according to programmed routing logic, history, account, time zone, and time of day. Customers connect with a relevant agent within one call and solve solutions as fast as possible. 

ACD reduces queuing time and collects information about customers giving to the head of call centers and observes real insights about every touchpoint with customers.

IVR. An interactive voice response system significantly reduces strain from agents because of the smart "key-pressed mechanism". Customers achieve the necessary result without disturbing any agent in a call center. As a result, the most obvious requests are processed by customers. It allows agents to tackle only demanding assignments. 

Call center management software is another tool that gives real-time insights about all activities of your remote agents. The main function of the software is tracking of:

  • Logging time;
  • Agent's adherence to schedule;
  • Absenteeism;
  • First Call Resolution rate;
  • Abandon calls;
  • Average handle time;

Automatic call distributor routes customers to the most relevant agent, while an interactive voice response system gives self-service options.

Value of KPI metrics for tracking the real service 

First call resolution (FCR). Resolving customer's issues from the first call is the best possible outcome for a call center. The higher the FCR rate, the more successful a call center is.

Average handle time (AHT) shows how much time each agent spent on resolving a particular issue and after-call work. The lower AHT the more your agent is productive. More challenging assignments increase AHT time, and it should be counted in overall performance.

Abandon call rate (ACR) indicates how many calls were hanging up before the agent could talk with a customer. In some cases, an abandoned call occurs due to technical problems. This is an obvious situation, and there is no way to avoid it. 

There are cases when the abandonment rate increases due to the agent's activity. As an example, if a customer waits in a queue for a long time, they're likely to hang up. In other cases, when customers couldn't find a solution from the first touchpoint.

In all cases, abandoned call rate should be included as a crucial KPI metric for tracking the history of interaction with the call center. 

Final statements 

Service level is something that all customers over the world are starving for. During economic transformation, customers became more demanding in terms of delivering a high level of customer experience. 

Voiptime Cloud delivered software for more than a decade. Our company helped companies to effortlessly switch their businesses towards remote work, maintain the high service level and prepare for market competition. Our customers are banks, manufacturers, e-commerce, and other small and mid-sized businesses. 


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