# How to Calculate FTE for Offline Queues?

In our Telegram Group, the most often asked question is “How to Calculate FTE for Offline Queue?” with certain TAT.

Today, in this article, I’ll try my best to solve the problem with some practical illustration on how we can calculate the FTE requirement.

Let’s start to explore!!

While we are trying to calculate the FTE for Offline Queue, the only thing which confuses us the most is the TAT which stands for Turn Around Time.

So, what is Turn Around Time and how is it decided?

Turn Around Time is the minimum or the Target time required to complete a task. The simplest way to calculate the Actual TAT is Turn Around Time = Exit Time – Arrival Time.

During the initial stages, the Turn Around Time is decided using the Time & Motion Study.

Time & Motion Study is a systematic observation, analysis, and measurement of the separate steps in the performance of a specific task for the purpose of establishing Turn Around Time and the Productivity(explained at the later part of this article).

The Study also aims at improving the TAT and the Productivity.

Once a proper Time & Motion Study is established, the Turn Around Time is decided and it becomes a target to achieve.

Some of the examples of Turn Around Time for Offline Queues are as below

• 100% in 4 Hours
• 80% in 2 Hours
• 100% in 24 Hours
• 100% in 48 Hours etc.,

Now we have the Target Turn Around Time. The next step is to Calculate how many FTEs are required to do the job.

### I have attached a excel file at the end of this article which shows all the calculation methods explained below.

Now we have the Target Turn Around Time. The next step is to Calculate how many FTEs are required to do the job. Before that, let’s look at some parameters required for the calculation.

• Productivity

While doing the Time and Motion Study, the firm will also decide how many tasks can be processed by an agent at a specific time. For e.g., 20 tasks per day. This is called as Productivity.

Although, there are many other terms for this, we will refer to Productivity for this article.

Two major examples of Productivity are shown below

• 20 emails per Day
• 15 emails per hour

Now, the above Productivity can be converted to AHT with just a simple calculation.

• 20 emails per Day = (3600*8)/20 = 1440 Seconds
• 15 emails per hour = 3600/15 = 240 Seconds

At the same time, the AHT can also be converted to Productivity with the below calculation

• 1152 Seconds = (3600*8)/1152 = 25 emails per day
• 300 Seconds = 3600/300 = 12 emails per hour

The 8 is the shift length and if you want to change it, you can. Also, if you want to calculate AHT in Minutes, please use 60 instead of 3600.

• Occupancy

Occupancy is the parameter where things get tricky. In Immediate Service Queues such as Inbound, Chat etc., the occupancy is an output derived from Erlang C. It is calculated as a weighted average of all the interval wise (15 mins or 30 mins or 60 mins) occupancies derived using the Volume, AHT and the Scheduled FTE.

But will it be the same for Offline Queues? I don’t think so

If you look at the Excel Attachment below, I have considered Erlang to calculate what would be the ideal Occupancy for 100% in 2 Hours TAT. Please refer to “Erlang Method – ASA” tab.

I have used the ASA formula to find the agents required for 15000 transactions spread across a week in an interval level with an AHT of 300 Secs. The Macros is edited a little to accommodate for the Interval Length.

As you can see, from the Excel file, the occupancy is coming at 94.86%. Is this a good occupancy to run at? Not at all. The agents would end up burning out which leads to higher attrition.

If your TAT is around 80% or 70% in 2 hours or 4 hours, you can use the SLA formula to find the agents required. Please refer to “Erlang Method – SLA” tab.

As you can see, from the Excel file, the occupancy is coming at 96.47% even for SLA scenario which is definitely very high.

### Therefore, for Offline Queues, it is always suggested to go with standard occupancy of 85% which will be ideal.

You can change the TAT, Volume or AHT in the file to see the change in Occupancy for yourself.

The Final Step!!

### FTE Calculation

There are multiple ways to calculate FTE for Offline queue and I’ve tried my best to shown as many ways as possible. Refer to the Tab “Workload Calculation” in the excel file.

• Method 1 – Using AHT

This is a simple Workload method where the Volume, AHT in Secs and Occupancy of 85% is used to calculate the FTE Required without Shrinkage.

• Method 2 – Using Hourly Productivity

If an agent has a target of 12 emails per hour, that means we would know the total email an agent can complete in a week just by multiplying 12 times 40 hours times occupancy of 85%. By this calculation, we found that an agent can complete 408 transactions a week. Therefore, we would need 37 agents to do 15000 transactions (i.e., 15000/408).

• Method 3 – Using Daily Productivity

If an agent has a target of 96 emails per day, that means we would know the total email an agent can complete in a week just by multiplying 96 times 5 days times occupancy of 85%. By this calculation, we found that an agent can complete 408 transactions a week. Therefore, we would need 37 agents to do 15000 transactions (i.e., 15000/408).

#### Now what if the productivity which was calculated using the Time and Motion Study already had Occupancy baked into it?

As told earlier, the Time and Motion study is a systematic analysis of a particular task. While studying the productivity, the firm may have already accounted for all the idle time in between, Therefore we don’t have to additionally add the occupancy again.

However, this has to confirmed by analyzing the study if we have the source or by asking the right person how the productivity target was determined.

Let’s see how to calculate FTE when the occupancy is already a part of AHT

• Method 4 – Using AHT

This is a simple Workload method where the Volume and AHT in Secs is used to calculate the FTE Required without Shrinkage.

• Method 5 – Using Hourly Productivity

If an agent has a target of 12 emails per hour, that means we would know the total email an agent can complete in a week just by multiplying 12 times 40 hours. By this calculation, we found that an agent can complete 480 transactions a week. Therefore, we would need 31 agents to do 15000 transactions (i.e., 15000/480).

• Method 6 – Using Daily Productivity

If an agent has a target of 96 emails per day, that means we would know the total email an agent can complete in a week just by multiplying 96 times 5 days. By this calculation, we found that an agent can complete 480 transactions a week. Therefore, we would need 31 agents to do 15000 transactions (i.e., 15000/480).

### Conclusion

To conclude, while we are calculating the FTE for Offline Queues, I would not take Erlang into consideration unless the TAT is 1 hour or less. I would always consider a standard occupancy of 85% provided if the same is being accepted by the Operations team too.

### Offline FTE Calculation Sheet

Thank you for reading and stay tuned

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