Forecast Accuracy

[LarryM13]

Hello all,

I would greatly appreciate if you can help me put a formula together to display the % accurate for the following forecast and actual results.

Please note these are random figures

<TABLE style="WIDTH: 739pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=986 border=0><COLGROUP><COL style="WIDTH: 81pt; mso-width-source: userset; mso-width-alt: 3949" span=2 width=108><COL style="WIDTH: 86pt; mso-width-source: userset; mso-width-alt: 4205" width=115><COL style="WIDTH: 81pt; mso-width-source: userset; mso-width-alt: 3949" span=4 width=108><COL style="WIDTH: 86pt; mso-width-source: userset; mso-width-alt: 4205" width=115><COL style="WIDTH: 81pt; mso-width-source: userset; mso-width-alt: 3949" width=108><TBODY><TR style="HEIGHT: 12pt" height=16><TD class=xl69 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 81pt; BORDER-BOTTOM: #ece9d8; HEIGHT: 12pt; BACKGROUND-COLOR: transparent" width=108 height=16> </TD><TD class=xl70 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 81pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=108>Jan-10</TD><TD class=xl71 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: #ece9d8; WIDTH: 86pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=115>Feb-10</TD><TD class=xl71 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: #ece9d8; WIDTH: 81pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=108>Mar-10</TD><TD class=xl71 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: #ece9d8; WIDTH: 81pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=108>Apr-10</TD><TD class=xl71 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: #ece9d8; WIDTH: 81pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=108>May-10</TD><TD class=xl71 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: #ece9d8; WIDTH: 81pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=108>Jun-10</TD><TD class=xl71 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: #ece9d8; WIDTH: 86pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=115>Jul-10</TD><TD class=xl71 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: #ece9d8; WIDTH: 81pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=108>Aug-10</TD></TR><TR style="HEIGHT: 12pt" height=16><TD class=xl68 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext 0.5pt solid; BORDER-BOTTOM: #ece9d8; HEIGHT: 12pt; BACKGROUND-COLOR: transparent" height=16>Actual</TD><TD class=xl72 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext 0.5pt solid; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right>$10,000 </TD><TD class=xl72 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right>$8,000 </TD><TD class=xl72 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right>($9,000)</TD><TD class=xl72 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right>$5,000 </TD><TD class=xl72 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right>($60,000)</TD><TD class=xl72 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right>($57,000)</TD><TD class=xl72 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right>($45,000)</TD><TD class=xl72 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" align=right>($100,000)</TD></TR><TR style="HEIGHT: 12pt" height=16><TD class=xl73 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext 0.5pt solid; BORDER-BOTTOM: windowtext 0.5pt solid; HEIGHT: 12pt; BACKGROUND-COLOR: transparent" height=16>Forecast</TD><TD class=xl74 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext 0.5pt solid; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" align=right>$15,000 </TD><TD class=xl74 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" align=right>$5,000 </TD><TD class=xl74 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" align=right>$5,000 </TD><TD class=xl74 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" align=right>($9,000)</TD><TD class=xl74 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" align=right>($57,000)</TD><TD class=xl74 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" align=right>($60,000)</TD><TD class=xl74 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" align=right>($1,000)</TD><TD class=xl74 style="BORDER-RIGHT: windowtext 0.5pt solid; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" align=right>$5,000 </TD></TR></TBODY></TABLE>

Thank you very much in advance!

 

[IsabelMatilde]

I guess I meant between 1% and 100% accurate

I have the same situation, I have an actual and a forecast with negative and positive numbers....so I cannot use the MAD and the Tracking signal because it does not work on this scenario. Any help?...I need to find the forecast accuracy.

 

[IsabelMatilde]

Have you ever found the solution? ...I have the same case and I need to find the Forecast accuracy....my numbers are positive and negative too.....

 

[West Man]

I don't think a forecast accuracy is even possible except when the actual is the same as the forecast. I think the best that can be done is a percent of the actual that the difference between actual and forecast is.

 

[AhoyNC]

See if attached link is of help.

http://www.axsiumgroup.com/?sc_itemid={636F1C5E-FD77-4F43-A371-E6985A1EAD37}

 

[IsabelMatilde]

Actual	Forecast	Error	ABS Error
-1000	800	-1800	1800
750	700	50	50
-1850	-1750	-100	100

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I appreciate your help but MAPE formula does not work either. The main issue here is that some of my actuals & Forecast are negative numbers like the example above. I am trying to calculate the tracking signal, but it seems MAD does not work with negative numbers.

 

[AhoyNC]

This link may help with tracking signal.

Measuring Forecast Accuracy: Approaches to Forecasting : A Tutorial - SCM | Supply Chain Resource Cooperative (SCRC) | North Carolina State University

 

[IsabelMatilde]

This link may help with tracking signal.

Measuring Forecast Accuracy: Approaches to Forecasting : A Tutorial - SCM | Supply Chain Resource Cooperative (SCRC) | North Carolina State University

I have reviewed mentioned link already, the problem is that we need to calculate the MAD formula to get the tracking signal and the MAD formula does not work when you have negative numbers in your actual or in your Forecast.

Any formula that help me to calculate the Forecast accuracy when we have negative numbers in the actuals and/or the Forecast please?

Thanks,

 

[AhoyNC]

You may want to try asking your question on a statistical forum. You could google them or here are a few listed below.

Statistics Help @ Talk Stats Forum
Statistics Forum - Statistics Help
Cross Validated