top of page
  • Writer's pictureVinay Vasudevan

Schedule Inflexibility - Basic Introduction

Updated: Feb 7, 2022

In Scheduling, the term Schedule Inflexibility or Schedule Inflex is used to measure the efficiency of the scheduling process, and it seems to be always tricky to understand.

In this article, I will try my best to explain Schedule Inflex and how to calculate it.

So, what is Schedule Inflex?

Schedule Inflex, sometimes also known as Shift Inflex or Schedule Wastage, measures additional staffing scheduled above the requirements due to certain constraints.

Note: The term Inflex stands for inflexibility, and it should not be replaced with the word influx.

Let's say the FTE requirement at 9:00 am is 25 and the requirement at 9:30 am is 30. We have a batch of agents whose shift starts at 9:00 am.

To meet the requirement at 9:30 interval, we will schedule 30 people at 9:00 am. This will result in having 5 excess FTE at 9:00 am interval.

The excess FTE is technically wastage, and unfortunately, it can't be avoided due to the above constraint. This wastage is known as "Schedule Inflex".

Various aspects or constraints contribute to the increase in Schedule Inflex, and some of them are mentioned below.

Call Arrival Pattern

Call Arrival Pattern is the major reason for Schedule inflex due to uneven arrival of the call in the intervals. Let's say we are dealing with two different arrival patterns, i.e., Normal Bell Curve and an M-Curve.

Though the volume and AHT remains the same for the day, we will have more inflex in the M-Curve comparative to the bell curve. This is due to the excess staff in those intervals between the two curves. This is better shown using the image below.

Labour law

Though this category may not contribute much to the schedule inflex, it is still considered a constraint.

The best example would be the part-timers. The inflex might have been reduced if we had options to include part-timers in the above M-Curve. However, in some countries, the concept of part-timers is still not implemented, which will create wastage.

Team-based scheduling

In some companies, the scheduling is built team-wise instead of agent-wise. This may create excess staffing in some intervals, which will lead to wastage.

Consecutive Week offs

This is yet another approach of certain companies to have good employee satisfaction. However, while improving employee satisfaction is good, it may have an excess headcount in some intervals.

Transport Constraints

In those companies where the transport is provided, the shifts are predefined due to the transport. This leads to having excess headcount.

Now let's come to the major question. How to measure Schedule Inflex?

There are various methods to calculate the schedule inflex; however, in this article, we will look at the simplest yet very effective method to calculate the schedule inflex.

I have attached an excel file at the end which contains the calculation; please make sure to see that


The process of calculation is broken into steps for better understanding

  • Step 1 - The weekly call volume should be divided into Day wise and Interval wise using the past interval wise pattern.

  • Step 2 - Once we have the interval-wise calls, we should use the Erlang Function to calculate the Interval wise requirements.

  • Step 3 - Against the interval-wise requirement, the FTEs have to be scheduled and further divided into interval-wise to compare the over/under.

  • Step 4 - Now, just by dividing the total FTEs scheduled and the Required FTE, the final Schedule Inflexibility is calculated.

From the excel file attached, the Schedule Inflex is computed as 118.32% (i.e., 22/19 = 118.32%). Therefore, this Inflex can be used for future forecasted volume to determine the FTEs to be scheduled without doing a Scheduling simulation.

Here is how it can be done. Let's say the weekly call volume is now 8000 instead of 7000(volume considered in the excel file). With the same AHT, the new Required FTE would be 21.

To calculate the FTE to be scheduled, multiply the previously calculated Schedule Inflex with the new requirement, i.e., 21*118.32% = 25(rounded). This way, schedule inflex can be used in the planning process.

Hopefully, with the above explanation, the Schedule Inflexibility now seems to be not so tricky😝

Thank you for reading, and stay tuned😊

Check out the weWFM Podcast on Apple or Spotify

3,206 views0 comments

Recent Posts

See All


Commenting has been turned off.
bottom of page