This this post, we’re going to look at methods, formulas and ways to calculate service levels in your call centre. For the most part, it’s quite easy to calculate everything; however, it’s often difficult to get your measurements correct!

The Service Level Formula

Service Level Percentage

Once you’ve input all the numbers, this formula will then give you a service level percentage.

For example, if your company has answered 100 calls within your service threshold of 20 seconds, whilst answering 125 overall – then your overall Service level is 80%.

Service Level With Figures

Working Out How Many Staff You Need

Working out how many agents you need in your call centre is easy; however, putting everything together without making small errors is a tough job!

In essence, there are a number of figures you need to gather first. Once this is done, we can start to put everything together and get the result you need.

1. Work out the number of calls that come in.

The first figure to start with, is how many calls are coming into your centre. It’s always best to start with a weekly figure, before moving into daily stats and ultimately hourly stats – depending on the granular control you require.

If you’re a Blue Telecoms customer, you should be able to compile this information easily by using the “Inbound Report” within your management interface.

Our advice, is to take a broad view of daily volumes for an entire month. By viewing such a large volume of data, you’ll be able to spot patterns in your daily calls too.

2. Work out the number of calls every hour.

To get your hourly figures, you can do one of two things:

  • Adjust your inbound report until you get hourly stats (Available in Blue Telecoms Legacy)
  • Divide your daily total, by the opening hours of your call centre. Read below for a warning!

Warning: The first option, is almost always better than simply dividing the daily rate. Most companies receive a higher volume of calls at different times of the day, depending on the client base, product offered and external variables. For this reason, simply dividing the daily rate by number of hours can potentially leave you understaffed at certain times of the day.

For this reason, we suggest using your PBX, dialler software or ACD system to obtain the exact stats.

3. Obtain your average handling, wrap up and disposition time

Average Handling Time (AHT), is basically the addition of Average Call Duration + Average Wrap Up Time.

4. Decide what your service level should be

For most call centres, the aim is to answer inbound calls within 20 seconds – 80% of the time. This becomes even more information in telesales operations, as Ofcom regulate the percentage of abandoned and dropped calls.

Ultimately, it’s up to you to decide exactly how quickly you want calls answered – without employing too many agents for that task at hand.

5. Call centre shrinkage

Shrinkage, comes from an old retail idea that not all the product within a shop can be sold at a profit. Some goods are spoiled, some can be stolen and others can be damaged – all leading to stock that’s unprofitable.

In the call centre world, shrinkage relates to time that agents should be available to take calls, but can’t for whatever reason. Agent shrinkage can happen for a multitude of reasons including holidays, sickness and toilet breaks.

For many call centre owners, calculating shrinkage is a heartbreaking part of this process; however, it’s always best to factor in some level of shrinkage so that your statistics show the true values.

Call Centre Helper have a handy guide to calculating your shrinkage here.

6. Use an Erlang Calculator

Now that you have the following:

  • Incoming volume of calls
  • The tested period
  • Average Handling Time (AHT)
  • The Service Level
  • Target Answer Time
  • Shrinkage

You can use an Erlang calculator to get your figures. Here are two calculators which do the job for free:

Regulations, Tips

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