Agents FTE In Call Centre Helper Excel Calc Jumps Related Articles How to Calculate Required FTE for Inbound Call Volumes What Exactly is FTE FTE Calculations Excel Based Erlang Calculator for Contact Centres – with Maximum Occupancy © Jane Kelly - Adobe Stock - 266139892 487 Filed under - Forum Agents FTE In Call Centre Helper Excel Calc Jumps From 6 to 8 I’m using the call-centre-helper-erlang-calculator-v5.5.xlsm and noticed that the FTE with shrinkage(=AgentsFTE) will jump by 2 agents. For example: Calls:14 Reporting Period:60 AHT:577 Required Service Level:80% Target Answer Time:60 Shrinkage:35% = Agents FTE of 6 If I increase the AHT to: 578 then Agents FTE jumps to 8. How should I interpret this? Question asked by Lex You Are Seeing the Effects of Shrinkage What you are seeing here is the effect of 35% shrinkage and a particular threshold. It’s easier to see this using the Online Erlang calculator https://www.callcentretools.com/tools/erlang-calculator/ So 14 number of calls per 60 minutes = 2.244 Erlangs – AHT 577 secs – 80% Answered in 60 secs – Shrinkage 35% – Max Occupancy 85%. Gives 4 Agents before Shrinkage = 6 agents after shrinkage Increase the AHT by one second takes you over a threshold 14 number of calls per 60 minutes = 2.248 Erlangs – AHT 578 secs – 80% Answered in 60 secs – Shrinkage 35% – Max Occupancy 85%. Gives 7 Agents before Shrinkage = 7.5 agents after shrinkage In the case of The Excel calculator this rounds it up to 8. Looking at the chart at the bottom of the Online Calculator if you had 4 agents before shrinkage (6 agents after shrinkage) you would have a service level of 79.9% which is just below the 80% threshold which is why it adds one agent before shrinkage. So the issue is around how you round the number of agents with shrinkage. 4 Agents before 35% shrinkage = 4 / ( 1 – 0.35) = 6.15 Agents after shrinkage 5 Agents before 35% shrinkage = 5 / ( 1 – 0.35) = 7.69 Agents after shrinkage One agent before shrinkage will add 1.54 agents after shrinkage. So depending on how you round up the number of agents will give different results. So the calculator is working as intended, but that is one of the challenges with Erlang as it works in increments of 1 agent before shrinkage. You should find that the Online Calculator will give better results. With thanks to Jonty Thanks Thank you very much for the explanation. I thought it was something like that but the confirmation was super helpful as my experience here is limited. Yes, the Excel function can only return one thing vs the On-Line Calculator can return the table Very much appreciated. With thanks to Lex Author: Jonty Pearce Published On: 12th Apr 2022 - Last modified: 18th Jul 2022 Read more about - Forum Recommended Articles How to Calculate Required FTE for Inbound Call Volumes What Exactly is FTE FTE Calculations Excel Based Erlang Calculator for Contact Centres – with Maximum Occupancy Contact Centre Reports, Surveys and White Papers Get the latest exciting call centre reports, specialist whitepapers and interesting case-studies. Choose the content that you want to receive. Contact Centre Reports, Surveys and White Papers Invites to exclusive Webinars & Events Weekly Newsletter