The topic of Service Desk staffing has remained an enigma and a point of much discussion and debate for years. Considering that Service Desk is such a matured service offering one would believe that calculating the number of resources required for a particular Service Desk would be a fairly easy task. However, this is one area where the most amount of time is spent while responding to a Service Desk RFP’s. Getting this aspect of the solution right is absolutely critical since this has the highest impact on the costing and also on your ability to meet SLA’s.
“Erlang C” is a well-established method of methodology of arriving at Service Desk staffing however it is not fully understood by many and also requires quite a few data points to get it correct.
In many cases I have observed solution architects getting into an analysis paralysis trying to come up with the staffing numbers. How many contacts, how many tickets, what is the FCR, AHT, expected SLA’s, coverage window, availability of Knowledge base, tools etc. etc. Not that these are not important data points however after taking into account all of these parameters if your staffing numbers are ± 10% off from what I am suggesting below then you need to relook at your numbers.
The method mentioned below is a quick way to ratify that the staffing numbers you have arrived at are in the right range. This will work for 90% of the standard Service Desks that operate with standard SLA’s and environments.
Number of Resources required for a service Desk = (Total Number of Contacts)/550
Where contacts = All touch-points that the Service Desk will receive via all touch-points like calls, email, web, chat etc.
I have had several situations where teams have spent days coming up with a staffing number after doing all the analysis and if they have done a correct job their number would be close to the number you would receive after using the above formula.
Don’t believe it? Try it.