In reply to Pablo.

Hi Pablo, that comet chart in the blog is a photo of a hard copy comet chart that was produced several years ago and I no longer have access to the raw data. But it should be easy enough for you to create a chart with any time series data where you have forecasts and actuals (and therefore, can compute the CV and MAPE (or whatever forecast performance metric you use)). Note that I used "Forecast Accuracy" so the comet chart angles from upper left to lower right. If you use some measure of "forecast error" (such as MAPE), the chart will angle from lower left to upper right. --Mike