Contact Center Forecasting Fundamentals Part 3: Closing the Staffing Gap

Charles Watson 13 min read Download as PDF
Contact Center Forecasting Fundamentals Part 3: Closing the Staffing Gap

Here is the third and final article in our series Contact Center Forecasting Fundamentals. As a refresher, part 1 focused on 'how to forecast workload' and part 2 dealt with 'how to master workforce forecasting'.

Now that you’ve forecasted your demand and the supply of agents, you’re ready to start deploying best practices to close the gap between the two. In this article, I’ll cover techniques for efficiently aligning staff to demand both short- and long-term. I’ll also look at how to determine the best method to cover staffing needs for a few weeks up to several months ahead. In each case, I'll walk you through a simple scenario, step by step.

Understand your staffing strategy

Before you actually allocate staff against the forecasted demand, it’s important to think about your contact center's overall staffing strategy. In some contact centers, it’s all about the customer and it’s OK to over-staff to be able to handle any spikes in call volume, handle time or shrinkage.

In other contact centers, the key goal of workforce management is to reduce cost, and staffing has to be efficient and tightly aligned with demand. Some call centers focus on the frontline agent first. In these cases, the staffing is generally similar to the customer-focused ones, where you over-staff and accept higher costs.

Find out where your company’s priorities are to ensure that your staffing supports your company’s mission. 

Determine the required number of permanent employees

First, you have to find out how many agents it makes sense to employ on a permanent (or fixed) basis. In other words, you are looking for the minimum number of FTE you need across all months of the year.

Table 1: FTE Required

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
215 250 265 243 201 209 213 234 247 259 289 297


In the above table, your lowest staffing point is 201. Taking this as a baseline, you know that you’ll need at least 201 agents every month. This is the number of permanent FTEs you should aim for. This should drive your hiring plans. Given the above numbers, some centers would staff up to 275 or 300 FTEs to ensure they can cover the peaks - in this case in the autumn and winter seasons. However, doing that runs the risk that they are overstaffed and run high idle times in the quieter months - in this case, the spring and summer seasons. This drives unnecessary costs and an inconsistent level of workload for agents across the year. What is missing is a flexible workforce strategy.

A flexible approach to staffing is much more efficient. Flexibility would enable us to scale up from a baseline of 201 agents to adapt to seasonal fluctuations while avoiding over-staffing.

Pro tip: Don’t think you will be able to arrive at the optimum permanent agent baseline right away. It may take a few years to do, but it’s good practice to have such a goal.

Flexible resourcing without hiring

Once you’ve established the number of permanent FTEs you need, it’s time to start thinking about how to close the gap between staffing requirements and staff availability. This typically involves hiring employees who are prepared to work flexibly, such as part-timers, but there are other solutions, too. Options to consider are  BPOs (business process outsourcers), seasonal workers, and temporary staff.  BPOs come in very handy, because they handle the seasonal spikes of calls for you, leaving you with the relatively easy job of handling a consistent workload with your in-house employees. Remember that outsourcers aren’t all in low cost regions and you can hire outsourcers in just about any market.

Flexibility and in-house contact center agents

Some flexibility options can be deployed with your own contact center employees.

Two of the most common methods are:

  • Time off at short notice, ideally unpaid, voluntary time off (VTO)
  • Overtime

These staffing ‘levers’ allow you to flex up or down a certain percentage of agents to cover the varying demand from month to month.  

In the example above, you need 289 and 297 agents in November and December, respectively. Overtime is a great way to cover this short-term need without adding staff. Looking at historical overtime acceptance rates will help you determine how much of the additional staffing needs can be covered with overtime. If there was 5% overtime in November and December during the past 3 years, you can probably assume that your agents will accept 5% overtime again.

Now you can apply the 5% to your staffing calculations for November and December and the number of additional staff needed for those months can be reduced by that amount. The same process applies to VTO in the slower months.

Keep in mind that these flexibility levers can also be pulled when you're experiencing sudden spikes or decreases in contact volume. That is explored in this very helpful resource about good practice in real-time management.

VTO and overtime aren’t the only levers. Depending on how your call center operates, you might have the option to switch agents to other call types until further notice or schedule them to spend part of the day on one type and the rest of the day on the other. If January is characterized by a peak for one call type, but not for another call type, then agents can be moved over to increase the staffing on the peak queue.

Doing this will very likely require support from training, and may have an impact on quality or handle time since agents are shifting focus from one queue to another. But you should definitely consider exploring how this option could work for you. It’s a great way to not only bring more flexibility into your staffing approach, but also gives agents an opportunity to take new call types and expand their skills on multiple service lines.

Creating a flexible staffing plan

Now that we’ve covered some strategic considerations and flexibility options, let’s build a real staffing plan.

Let’s look again at our example. In the table below, you see our staffing requirement (based on the workload forecast) compared to the staff that are available (based on the workforce forecast). Let’s assume that we are starting the year with 245 agents and we expect to lose two every month due to attrition.

Table 2: Requirement vs. actual

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Required 215 250 265 243 201 209 213 234 247 259 289 297
Action 245 243 241 239 237 235 233 231 229 227 225 223


Based on the numbers in Table 2, I'd recommend the following set of actions to make sure that we achieve our goal of closing the staffing gap each month.


We need to get 30 FTE to take time off, ideally VTO (unpaid Voluntary Time Off) to scale down our staffing level. If that’s not possible, we can schedule shrinkage activities in January.

For instance, when looking at staffing levels in February, we see that this month our contact center is slightly understaffed. If there is any training planned for February that can be brought into January, we have an opportunity to both reduce the February understaffing while working to solve the January overstaffing. Win-win!


Even though February is understaffed, it’s not understaffed by much on a percentage basis. In fact, it’s less than 3%. This is likely smaller than the margin of error in the forecast and consequently, I wouldn’t take any drastic measures to solve this staffing gap. I would consider 7 FTE of overtime to close the gap as a backup plan, but only offer the overtime if I actually see unexpectedly high volumes coming in.


If you look at March in isolation, a natural reaction would be to start hiring, because the deficit is 24 FTE.  But if you look to the next several months, the requirements go down and this will leave you heavily overstaffed. The gap of 24 is equivalent to 9% of your staffing requirement, which is likely much more than you could resolve with overtime. The best options here are:

  • Move as much shrinkage as possible out of the month
  • Identify opportunities to move agents from another queue into this one for the month; if they can start in February, that is a bonus
  • Plan overtime to cover the balance

As you’re looking ahead, moving more PTO (Paid Time Off) from March into May and June isn’t a bad idea, either.


April is understaffed by 4 FTE (1.6%). I wouldn’t worry about this month.


I’m going to cover all three of these months together, because they are all similarly overstaffed and are characterized by the lowest staffing requirements of the year.  

You should take action here. It’s easy to look at these months and think ‘OK, we can relax about service level’. But because we aim to excel in all we do, that isn’t good enough!  We’re going to make this even better.

Given the overstaffing, you have an opportunity to allow more training or other activities that help make your agents better at what they do. This is a great opportunity to invest in your employees so they can further develop or improve their skills and thus be sharp for the peak coming up later in the year. You can move other shrinkage activities from other months as we showed earlier, to help ease pressure on those months.


August is within 1.2% of requirement. Don’t waste any time me. This small discrepancy falls within the noise range of the forecast and can safely be neglected.


OK, now things are picking up as we get into the peak season for the business. Both of these months are understaffed and the requirements only go up in November and December. This is where you really want a class of new hires.  

Keep in mind that every business has a different capacity for training new employees. A common class size of new hires is 20, which means you’d add one class of 20 FTE to start in September. Then you’d fine-tune the staffing with overtime and VTO.

Note:  Always expect higher than average handle time with new hires. If you have 20 new hires starting in September, they are unlikely to be fully productive in that month.  If their handle time is double that of a tenured agent, then they will only produce the result of 10 FTEs. Good WFM applications will let you assign skill levels with date ranges to automatically take this into account.

Look at the historical learning curve for new hires to understand the effect on handle time. You may actually need these agents to start taking calls in August so they bring their efficiency levels up to 100% in time for September.


This is it!  Peak season for our pretend contact center is here and it’s time for us to shine for our customers. Most businesses have a seasonal peak and it means more than just higher call volume. It actually represents the time your customers need you the most! It’s also the time that many contact centers are understaffed, so your customers spend a lot of time waiting in queue. We don’t want that. So let’s solve it.

First, imagine you already have 20 agents from your last hiring class. You likely need another 20 to get yourself within overtime range. Look at your learning curves and see if you need to bring them in earlier. It potentially makes the most sense to bring in 40 FTE in September and VTO your excess staffing in September and October.

Second, if you haven’t done so already, you should minimize your planned shrinkage in November and December. It’s not realistic to allow zero time off, even in peak season. You can’t expect agents to go two months without vacation - in fact, this would likely lead to increased absenteeism. You should, however, minimize all other forms of shrinkage. That means no training and very limited coaching time. Remember,  we invested time in coaching and training during the preceding months, January to October. Now, it’s time to execute.

Now that you have a plan, what’s next?

Best practice is to meet your recruiting and training departments at least every month. Staffing requirements will continually change as new data comes in and you revise your forecasts. There will always be constraints on the number of people you can hire and train each month. 

For recruiting, the limiting factor may be the number of recruiters in the department or the number of qualified candidates available in the market. For training, it may be the number of trainers or the number of available training rooms. 

There are a couple of other things that you can do to make sure that you successfully execute your plan and deliver on service-level goals. One important area here is real-time management.

Some final words

I hope you’ve been able to take some useful information from this three-part series on forecasting fundamentals. This is definitely a topic where workforce management has a major impact on your company’s success. Planners can adopt a purely analytical role, like a human calculator. Much better for the company - and your career - is to develop strategies that align with the objectives of your leadership team. When you do that, you become an invaluable asset to your business!

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