Understanding estimated callback time (ECBT)
Learn how Estimated Callback Time (ECBT) is calculated and how it influences callbacks.
Calculating the Estimated Callback Time (ECBT) is a central function of Mindful that allows the system to accurately predict the time that a customer can expect to receive a callback.
Many factors come into play to determine the ECBT at a given moment, including talk-time metrics, waitlist forecasts, and the configuration of each Call Target. Different formulas are used to calculate the ECBT in different scenarios.
Overview
This article covers the following topics to help you understand how ECBT is calculated and what impacts you can make.
- Definition of terms
- ECBT formulas
- Impact of next-day callbacks
- Understanding waitlist priorities
Definition of terms
Before we begin to understand the way in which ECBT is calculated, let's define a few important terms that we will see in the ECBT formulas. Use the following table as a reference to understand the terminology used throughout this guide.
- Forecast waitlist size
Forecast waitlist size determines the amount of time expected to be taken up by calls that will be launched between now and the expected launch time of the current call. For Call Targets with large forecast waitlist sizes, the value is automatically increased to account for retry attempts.
Forecast waitlist size is recalculated after each call is answered, scheduled, or ended.
- Forecast queue size
- Forecast queue size predicts the number of calls placed in the high-priority holding queue that have not yet been answered by an agent.
- Average seconds per agent answer
Average seconds per agent answer tracks a rolling average of the time elapsed between agent answer events. Mindful uses a configurable rolling average to ensure that this metric remains as accurate as possible and responsive to changing queue conditions.
You can refine the calculation for the average seconds per agent answer by adjusting the Minimum Averaging Window in Minutes and Minimum Number of Data Points to Average.
Mindful only tracks calls that it has handled and sent to your contact center. Calls in your ACD are not included in this or other calculations.
- Minimum Callback Delay
Minimum Callback Delay is a configurable setting that sets a minimum length of time that Mindful will wait before dialing an ASAP callback.
We recommend setting Minimum Callback Delay to the same value used for your offer threshold--the minimum amount of wait time that will trigger a callback offer.
ECBT formulas
The formulas used to calculate the ECBT vary based on whether you plan to use a high-priority or normal-priority holding queue as the Callback Phone Number destination. Using a high-priority queue is the recommended best practice in most scenarios.
Two different scenarios can impact the calculation of ECBT:
- High-priority queuing for Customer First or Agent First callbacks
- Normal priority queuing for Agent First callbacks only
High Priority Queuing
(Forecast waitlist size + Forecast queue size + 1) * Average Seconds per Agent Answer + Minimum Callback Delay = ECBT
This formula takes the forecast number of calls on the internal waitlist, adds the forecast number of calls in the high-priority holding queue (the destination reached by the Callback Phone Number), then adds 1 to represent the current call. The resulting sum of total pending callbacks is then multiplied by the Average Seconds per Agent Answer, then the Minimum Callback Delay is added as a buffer.
Normal Priority Queuing
(Forecast Queue Size + 1) * Average Seconds per Agent Answer + Minimum Callback Delay = ECBT
This formula begins with the same calculation used for high-priority queuing, but removes the forecast number of calls on the waitlist.
If you wish to use normal-priority queuing for the callback destination on your ACD, then you must set the Max Queue Depth to "unlimited". This allows the Call Target to bypass the internal waitlist and send all callbacks to the normal-priority queue when the Minimum Callback Delay has been reached.
Punctuality Buffer
When Announce ECBT is enabled, customers will hear an estimated time quoted with a 20% buffer above and below the actual calculated time. There is also a three (3) minute buffer on each end of the ECBT built-in for punctuality purposes.
In this example, a customer calls in when the ECBT is currently 10 minutes.
- 10 minutes + 20% (2 minutes) + 3 minute buffer = 15 minutes
- 10 minutes - 20% (2 minutes) - 3 minute buffer = 5 minutes
In this case, the customer will hear "You can expect a callback between 8 and 12 minutes from now" (the ECBT +/- 20%). However, the system considers a callback occurring within 5-15 minutes (the ECBT +/- 20% and +/- 3 mins.) to be punctual.
Impact of next-day callbacks
When the End of Day Handling settings are configured to offer next-day callbacks, some callbacks from the current day can impact the ECBT for calls early the next morning. Since the system must take next-day callbacks into account on the next morning, the ECBT can increase accordingly.
If the Max Queue Depth setting is enabled, Mindful will limit the number of next-day callbacks placed at once to ensure that the maximum value is not breached.
Mindful takes the Next Day Callback Delay into account when adjusting the ECBT for next-day callbacks. For example, with Next Day Callback Delay set to one hour, Mindful would know that next-day callbacks from the prior day will not impact the ECBT for the first hour of the current day.
Mindful only considers next-day callbacks that would be ready to launch before a new inbound call when calculating the ECBT.
Understanding waitlist priorities
When a callback cannot be dialed due to the current queue conditions (based on the Max Queue Depth and/or Max Active Calls settings), it is added to an internal waitlist. Two separate waitlists are used, with different levels of priority, based on the callback type.
ASAP callbacks are added to their own waitlist, while scheduled callbacks and retries are combined into a second waitlist with a higher priority.
Setting different priorities for different types of callbacks helps to ensure that customer expectations are met as closely as possible.
- Customers expect scheduled callbacks at a specific time, and they may have received a Reminder Notification to reinforce the scheduled time, so it is important to dial those callbacks as close to the scheduled time as possible.
- Retries are callbacks that were intended to be answered already, and it's a best practice to dial retries at a regular interval.
- For ASAP callbacks, customers may have been quoted the Estimated Callback Time (ECBT) with a +/- 20% buffer, or they may not have been quoted an estimate at all. Punctuality is still important, but less important than scheduled callbacks or retries.