Timeseries Multiplicative Triple Forecasting model

Ron04

New Member
#1
I have developed a Timeseries Multiplicative Triple Forecasting model. (Holt Winters model as baseline) . With my Alpha,Beta and Gamma parameters I am able to forecast future demand.That is not the issue. It provides 26 .8 % reliablity.That obviously has to be at least 60 % or higher.

Now for automatically function and calculating the advised and optimal Alpha,Beta and Gamma ( I currently do this manually without Excell formula and use Wessa .net ) , I would need help to further develop this model. I have this set up in Excel.
Is there anyone on this forum who can help me with this?
Maybe advise to use another Online Model or Statistical program ? or advise how to improve within Excel and can advise me on formula's to use?
How do i achieve a 60 % or higher forecast reliablilty ?
 

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staassis

Active Member
#2
General observation: Excel is a primitive package. There is much more time series functionality in packages like R, Matlab, Stata and EViews. This functionality will help you run diagnostic tests on the estimated model and extend the model accordingly. In particular, you may want to focus on the residuals implied by your model. Are they white noise or are you seeing some structure unexplained by your model?
 
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Ron04

New Member
#3
Excel
Excel looks not usable in this case. Their ETS function output is not even close.
If I change ABG* each separately, the accuracy percentage of forecast compared to realistic Sales increases. and comes very close to the actual number and sometimes Is equal to it, my residuals improve on accuracy and so my first conclusion is that I have inaccurate ABG* parameters. I get these by using Wessa.net (times series) ,It advises me of the ABG*, but I think they are not accurate enough. I also probably have the incorrect seasonal pattern, which is difficult to detect.

R program
1.Do you think 'R' can provide a higher accuracy and how does it work with forecast accuracy ?

*(ABG = Alpha , Beta and Gamma parameters)