Forecasting issue

Dear Forum Members,

I have a problem with forecasting. Attached is the file in which I forecasted sales for 2018. On the left side is an example I used from the internet. On the right side is the same method applied to my own data. Or at least I did best to duplicate the method. I did manage to duplicate everything, however the forecasted sales seem way off. My question to you is if you could be so kind to take a look at the Excel sheet attached.

Thank you in advance, hope to hear from you soon.

Cordially,

Bremmes

Hello, Bremmes.
I have batched up your data in groups of eight and seven and results came out closer than expected, but I'm not sure if it makes any sense to you.
Take a look.

Godspeed!

Dear Estevaoba,

Thank you for your quick response! It indeed looks a lot better! I can work with this. I only have one question. What is the reason that you batched the data in groups of 8 and 7? Is it also possible to keep the data in its previous form? My original set of data is in weeks so that I can see the change of sales and forecast weekly sales. Please let me know what you think, feel free to sugest perhaps other (better) methods for forecasting weekly sales data.

Thank you in advance for your help!

Cordially,

BremmesN

Well, I did it for no particular reason. It just occurred to me that the original example had far less figures to deal with. So I decided to bring yours closer to that.
I am no expert, but I thought that maybe you'll find some explanation in the book the method comes from.
Good luck!

Alright, so you are not familiar with a method that suits my set of data best?

BremmesN

No, I'm not.
Sorry I can't help you on that.
Take care, my friend!

Dear Estevaoba,

Alright, no problem. I will post this thread once more and perhaps someone else can help me.

Thank you for your help.

Cordially,

Bram Nijman