This module provides the Erlang C and Erlang B formulas as Excel AddIns. While other providers charge a lot for software products of these widely used functions, CC-Logic offers this module for free and unlimited. However, CC-Logic recommends using AnswerWIN and AnswerXLS. These functions are much better than Erlang C and Erlang B.
The major difference lies in the assumptions on the behavior of waiting callers. While Erlang assumes that callers never hang up no matter how long they must wait, AnswerWIN and AnswerXLS include the possibility that callers abandon after a certain waiting period. This means that AnswerWIN and AnswerXLS takes Lost Calls into consideration while Erlang ignores them. Therefore AnswerWIN and AnswerXLS are much closer to real life than Erlang.
Economically, lost calls have a very high impact on the profitability, since each lost call can represent a loss of sales or even the loss of a customer to a competitor. AnswerWIN and AnswerXLS therefore allow to economically determine the optimal size of a call center by using the trade-off between cost of more staff and a reduction of lost calls. Erlang cannot provide that.
After installing the Excel Plug-Ins once, you will find a new functions category in Excel called “ErlangXLS”. It allows you to call all ErlangWIN functions from anywhere whithin your Excel spreadsheet.
After selecting the right function (e.g. “Service Level”, “Occupation”, etc.) you will be asked interactively to provide the function arguments (like number of expected calls, talktime, etc.). Here, you can either provide a fixed number, or you can link to a cell in your spreadsheet where the value can be found. Each function argument is also explained interactively.