Is Overhang Distorting Your Staffing Calculations?

In this instalment of our video series exploring what you need to know about forecasting, and what they won’t tell you, Call Centre Helper’s Jonty Pearce explains daily profiles and reporting intervals.

Daily Profiles and Reporting Intervals

Once you’ve got your seasonality data and you’ve de-trended and de-seasonalized it, and built your model, then once you’ve got a weekly staffing requirement, you need to try and put on some sort of daily, or weekly, profile to the data to generate your staffing requirements.

There’s lots of articles on Call Centre Helper about how to do that. One of the things a lot of people tend to forget is that call arrivals tend to bunch up around the hour.

This is sort of human behaviour, and what you typically find is something like 40% of overall traffic tends to happen in the first 15 minutes of the hour, about 30% in the last quarter of the hour, and the remainder tends to happen between these periods.

And if you think why is that?

We live in a world where a lot of things are scheduled around the hour, so you get to work and you’re scheduled to be at work at 9:00. So you’ll make a call to the call centre just before you get to work, or just after you’ve got to work.

You have your lunch break – you might be calling the call centre at the beginning of your lunch break, and those tend to be scheduled on the hour.

So you tend to get a lot of stuff bunched up. People go to a meeting. I’ll make a call to the contact centre before the meeting. So one of the things you’ve got to look at is that in terms of how you look at your reporting intervals, it’s much better if you can report on a 15-minute basis.

So you break your call volumes, or contact volumes, down by 15 minutes. Now there is one thing you’ve got to be careful of, and it’s something called overhang.

If your average call duration, for instance, is, say, 25 minutes, you know if you had a very long technical type call, then what you’d find is you’ve got effectively calls going on from one period carrying on into the next period, and that will tend to distort your staffing calculations.

A good rule of thumb is that your average handling time should not exceed 50% of the reporting period. So if your average handling time is 7 and a half minutes, or more, then the 15-minute model won’t work so well and you probably ought to be working on a half-hour basis.

There may also be some limitations that your ACD or CCaaS system runs on a half-hour output, in which case you need to use that.

For more in this series watch these videos next:

• If It’s a Forecast – It’s Wrong
• Getting Started With Forecasting