Setting Up Your Baseline in Excel Sales Forecasting
Part of the Excel Sales Forecasting For Dummies Cheat Sheet
You need to provide a solid baseline (history) in order for your Excel forecast functions to work accurately in Excel sales forecasting. This chart shows you some ways to arrange data for your baseline:
| The Issue | How to Deal with the Issue |
|---|---|
| Order | Put your historical data in chronological order, earliest to latest. |
| Time periods | Use time periods of approximately equal length: all weeks, all months, all quarters, or all years. |
| Same location in time | If you're sampling, then sample from the same place. Don't take January 1, February 15, March 21. Instead, use January 1, February 1, March 1, and so on. |
| Missing data | Missing data is not allowed. If you have every month except, say, June, find out what June's sales were. If you can't, get the best estimate possible — or start your forecasting with July. |
