Forecast Funcation

  • Thread starter Thread starter Strangways
  • Start date Start date
S

Strangways

Can anyone help, I am looking to use the Forecast funcation within Exce
and cannot get it to work properly.

I have 3 years worth of Data for parts that we sell and would like t
have a forecast worked out automatically within Excel.

Excel file attached with 2 year example and a dummy part. Need t
predict in this case the qty for Oct-03.

Thanks for your help.

regards
Simo

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| Attachment filename: forecast_dummy.xls
|Download attachment: http://www.excelforum.com/attachment.php?postid=368286
+----------------------------------------------------------------
 
Hi Simon,

I had a look at your spreadsheet. I changed it slightly to make it easier
to work with.

The top row is simply the months Mar thru Oct.
Next row is Year 2002 data.
Next row is Year 2003 data.

I then graphed it. You can see readily that the two plots are almost
identical.

You mention in your message you want Excel to create forecasts
automatically. You are going to have to tell XL how you want it to
forecast. There are numerous methods of forecasting. In your simple
example, I would simply use Oct 2002 as my forecast for 2003.

But other plots might not align themselves so nicely.

Thus, I think you will have look at your data and get a better feel for how
the correlations work, and then what method you want to use to forecast this
year's values.

As an aside, a commercial product called Crystal Ball does time series
forecasting. It works hand-in-glove with Excel. You can learn more by
going here...

http://www.crystalball.com/index.html

I don't think this message was of great assistance to you. But without
becoming immersed in your data, it is hard to simply say, "do this, and your
forecasts should be very close."

Best of luck.

Regards,
Kevin
 
Hi Kevin,
I don't think this message was of great assistance to you. But without
becoming immersed in your data, it is hard to simply say, "do this, and your
forecasts should be very close."
Click to expand...

I disagree. What you did was way beyond the call. I was curious about this
problem, and I suspect others were too, but I tire of saying "don't attach
workbooks if you really want a response". I just won't do it, and I am not
alone.

And, without having seen the data, your response goes a long way in giving a
picture of what the data look like; your suggestions sound great.
Regards,
Dave Braden

Kevin Stecyk said:
Hi Simon,

I had a look at your spreadsheet. I changed it slightly to make it easier
to work with.

The top row is simply the months Mar thru Oct.
Next row is Year 2002 data.
Next row is Year 2003 data.

I then graphed it. You can see readily that the two plots are almost
identical.

You mention in your message you want Excel to create forecasts
automatically. You are going to have to tell XL how you want it to
forecast. There are numerous methods of forecasting. In your simple
example, I would simply use Oct 2002 as my forecast for 2003.

But other plots might not align themselves so nicely.

Thus, I think you will have look at your data and get a better feel for how
the correlations work, and then what method you want to use to forecast this
year's values.

As an aside, a commercial product called Crystal Ball does time series
forecasting. It works hand-in-glove with Excel. You can learn more by
going here...

http://www.crystalball.com/index.html

I don't think this message was of great assistance to you. But without
becoming immersed in your data, it is hard to simply say, "do this, and your
forecasts should be very close."

Best of luck.

Regards,
Kevin
Click to expand...
 
Hi David,
I disagree. What you did was way beyond the call. I was curious about this
problem, and I suspect others were too, but I tire of saying "don't attach
workbooks if you really want a response". I just won't do it, and I am not
alone.

And, without having seen the data, your response goes a long way in giving a
picture of what the data look like; your suggestions sound great.
Click to expand...

Thank you David for the kind words. I was curious, so I had a look. It was
hard (or impossible) to give a strategy for a whole portfolio of part with
only a few data points. I hope Strangways recognizes that there is not a
"simple" and confident way of making forecasts without having a good
understanding of the data.

Again, thank you.

Best regards,
Kevin
 
David J. Braden said:
Hi Kevin,
I don't think this message was of great assistance to you. But without
becoming immersed in your data, it is hard to simply say, "do this, and your
forecasts should be very close."
Click to expand...

I disagree. What you did was way beyond the call. I was curious about this
problem, and I suspect others were too, but I tire of saying "don't attach
workbooks if you really want a response". I just won't do it, and I am not
alone.

And, without having seen the data, your response goes a long way in giving a
picture of what the data look like; your suggestions sound great.
Regards,
Dave Braden

Kevin Stecyk said:
Hi Simon,

I had a look at your spreadsheet. I changed it slightly to make it easier
to work with.

The top row is simply the months Mar thru Oct.
Next row is Year 2002 data.
Next row is Year 2003 data.

I then graphed it. You can see readily that the two plots are almost
identical.

You mention in your message you want Excel to create forecasts
automatically. You are going to have to tell XL how you want it to
forecast. There are numerous methods of forecasting. In your simple
example, I would simply use Oct 2002 as my forecast for 2003.

But other plots might not align themselves so nicely.

Thus, I think you will have look at your data and get a better feel for how
the correlations work, and then what method you want to use to forecast this
year's values.

As an aside, a commercial product called Crystal Ball does time series
forecasting. It works hand-in-glove with Excel. You can learn more by
going here...

http://www.crystalball.com/index.html

I don't think this message was of great assistance to you. But without
becoming immersed in your data, it is hard to simply say, "do this, and your
forecasts should be very close."

Best of luck.

Regards,
Kevin
Click to expand...


Automatic Forecasting Systems makes available a piece of Freeware
called FreeFore which can be used in conjunction with Excel . It
tailors or customizes the model to the data rather than trying to
forece the data into a pre-set collection of models.

http://www.autobox.com/freef.exe

Regards

Dave Reilly
AFS
Click to expand...
 
Hi Simon,

We have developed a powerful forecasting Excel addin that
may or may not be useful to you (depending on your data
and how you want to predict). It uses our own AI
technology to discover patterns in your data.

See http://www.pececillo.com for more info.

It's just a BETA at the moment, but it may still be of
help to you.

Gabhan Berry
AI Prediction in Excel
http://www.pececillo.com

-----Original Message-----

Can anyone help, I am looking to use the Forecast funcation within Excel
and cannot get it to work properly.

I have 3 years worth of Data for parts that we sell and would like to
have a forecast worked out automatically within Excel.

Excel file attached with 2 year example and a dummy part. Need to
predict in this case the qty for Oct-03.

Thanks for your help.

regards
Simon


+----------------------------------------------------- -----------+
| Attachment filename:
Click to expand...
forecast_dummy.xls |
 
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