Thanks for writing this comment Bryce.

Am happy that the video helped you. Thanks for leaving this comment.

+Andy Ryan Thanks for leaving the comment. All good things are always simple!!

Do look at the other videos on forecasting as well.

Thanks for leaving this comment. Happy that the video was useful to you. Do also check the video on Measuring Forecasting Accuracy.

Sorry for the late reply. I somehow missed your message. The 570 is a number I have assumed here. The yearly sale could have been obtained by any time series method. The yearly demand is not affected by seasons as all versions of seasons are inside the year and hence calculating that is easier.

he had made mistake..instead of 570 , 143.34 average of 1st quarter of all 4 years need to be taken and multiply it by seasonality factor of 1.0305 to get forecast of quarter 1 and so on for quarter 2, 3,4 .

+Rosario Dizon That is assumed to be given. Maybe some other method was used to derive it.

@@piyushashah1 Why would someone try to figure out the forecast if that amount was already given?

@@ricardoguzman7518 You would need monthly or quarterly demand forecasts for production or fullfilment. it is a normal process to disaggregate forecasts like this from some aggregate forecast.

I am not sure if you can use these methods to directly predict the demand for next Christmas. While you could use the Holt-Winter's model as a base, you would have to add contextual factors to account for current year.

HI Swati, I'll try. Thanks a lot for the suggestion.

Do you mean percentage of sales method? Why do you need to do that? Can you give me details please?

Thanks for leaving the comment Aay...there are other forecasting videos as well, do have a look.

That is an assumed number Anshul. Typically we could use some form of time series of regression to arrive at it. I have a video on that.

hello Rishu, thank you for this comment. The actual demand numbers already have the influence of seasons. So, averaging them and adding the effect of seasons again on them would not be valid. The ideal way is to use some method to find deseasonalized demand forecast and then add the effect of the season. I have used aggregate demand forecast from an unmentioned method as the deseasonalized demand. There can be many other ways to arrive at the deasonalized demand other than what I have done. Hope this helps.

+ankushzap With this method you need that '570'. We can use some other method, maybe regression to get that.

You can... But I won't trust the accuracy of such one year based indices.

@@piyushashah1 Thank you for responding, but can you please tell me why wont you trust its accuracy? You see I am new to forecasting, and I wanted to know if a company only has past data for 1 year, how should it go about forecasting for future months mitigating the seasonal effects?

@@smaranrai4898 There could have been some random variation in a specific period. If you just have one year data, you will assume that the random variation is a part of seasonality. However, if you have multi-period data, such random variations tend to average out and we get more accurate seasonality indices.

@@piyushashah1 Thank you so muchh piyush!! This makes things much clearer!!!

Yanuar Anaba Wahyuesa We should check the Forecast for errrors. There is a separate video on the different ways to calculate the errors.

Asima Shahzadi sorry, can you elaborate on your question?

As mentioned in the video, you can use some other method to forecast that.

That is an assumption for this video. In actual scenario we can get it from linear regression or some mechanics performed on yearly demand data.

I have assumed that number for this video. We can get it from moving average, regression or any of the other methods explained in other videos.

It is an assumed number that we could have obtained from regression or any other method.

Daniel Burke Yes, and sorry. But the free tool I have has this limitation. I hope I can get a better method or a tool.

There are pdfs online that discuss Croston method. For example this: courses.edx.org/asset-v1:MITx+CTL.SC1x_1+2T2015+type@asset+block/w4l2_NewIntermittentProducts_ANNOTATED_FINAL.pdf. I have never used this method am not sure how exactly to use this.