In our last tip, we explained a simple math error we found in a home-grown cap planning spreadsheet that we were reconciling while converting to our cap planning system. Here is another fun error to giggle about. I may have told this one before, but it is fun.
We worked with a large, well-known travel company, and were trying to figure out the difference between their old spreadsheet’s staffing calculation and our new system’s staffing waterfall. It took us a while, but we found this weird calculation in their spreadsheet:
Staffing = Erlang C (volume, handle time, service goal) +15
We asked the analyst (now, a good friend) “What was this plus 15?” His response is so normal in our contact center world: “I don’t know! I inherited this spreadsheet four years ago!”
When we looked at other groups, we found the same sort of thing, staffing equations with differing fudge factors added to their staff calculations. In all, they added maybe a hundred extra agents to their operation and $5MM to their annual cost. Nobody knew why, the person who built the spreadsheet was long gone. $20MM over the four years. Was it necessary? No. The Erlang C had its own staffing over-bias that added extra agents, the extra fudge was probably to cover some shortfall they experienced at one point in time.
Here's the lesson: We all inherit work-product from our predecessors. It may be of value to recreate some of these tools ourself to either remove any of their mistakes, or to simply understand the process better.
Another lesson: In cap planning, fudge factors are a bad crutch. A problem with adding a fudge to an Erlang calculation is that the fudge itself is probably not constant, meaning it will change over time.
Note: This week’s tip is provided by Ric Kosiba of Real Numbers. Ric is a charter member of SWPP and Managing Partner at Real Numbers, a contact center strategic planning software company. He can be reached at ric@realnumbers.com or (410) 562-1217. Please know that he is *very* interested in learning about your business problems and challenges and knows a bunch about capacity planning. Feel free to set up some time at realnumbers.com. Follow him on LinkedIn! (www.linkedin.com/in/ric-kosiba/)
