Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

The ultimate Microsoft Fabric, Power BI, Azure AI & SQL learning event! Join us in Las Vegas from March 26-28, 2024. Use code MSCUST for a $100 discount. Register Now

Reply
PowerBI_77
Frequent Visitor

My forecast is constant each year!

Hi all!  I'm using Power BI to produce a forecast for the next 5 years, based on monthly volume data since 2007.  My chart of the forecast looks like this (green line is actual monthly data, dotted black line is trend line and solid black line is forecast):

 

5yr Forecast.JPG

 

As you can see, a trendline on the data shows a gradual upward trend.  However the 5 year forecast shows the exact same values each month for each year - e.g.  Jan-19, 20, 21, 22, 23 all show the same forecast value.  All the Februarys show the same forecast value, etc.  It's just the same pattern repeated 5 times.  Is this what is meant to be shown?  Unless I'm missing something obvious, I would think that Power BI would show the forecast data increasing each year based on the existing trend?  

 

PS I have set seasonality to '12' as my data is monthly.  

 

Regards,

Lee

 

7 REPLIES 7
Mohanad-Mustafa
Advocate III
Advocate III

I am having the same issue even with 4 months of data and only forecasting one month of data. If I use the Anamolies option istead of forecase, it gives a bit more accurate results when it analyses the sales histroical data. The forecase option is far from reailty, I think the problem lies with the type of data we are feeding into Power BI, it might less fluctuations in the data to be able to tell the real forecast. 

v-yulgu-msft
Employee
Employee

Hi @PowerBI_77,

 

Please leave the "Seasonality" option empty for a test.

 

Regards,

Yuliana Gu

Community Support Team _ Yuliana Gu
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Hi Yuliana.  Thanks for your reply.  If I leave the Seasonality option blank (so it resorts to the 'auto' setting), I get the following chart:

 

Forecast Auto Seasonality.JPG

 

This forecast seems to more closely match the trend of the data, but I now lose any variation in the data and I just get a straight line! 

 

Regards,

Lee

Hi All.  Just a small update on this issue.  I've now tried experimenting with a date slicer on the dataset and I've noticed that if I exclude a portion of the early data, at a certain point Power BI will give me a forecast which looks more sensible.  For example if I only look at monthly volumes from Sep-2011 onwards, I get the following chart:

Data with Slicer.JPG

 

At least now, my forecast is showing variation and is following the trendline (dotted line).  My theory is that Power BI will only apply a similar trend to the forecast data if the R-squared value is above a certain value?  Or if the correlation coefficient is above a certain value?  

 

Just for comparison, here again is what the forecast looks like if I reset the slicer (using the entire dataset):

Data with Slicer Reset.JPG

 

Does this seem consistent with anyone elses experience with forecasting in Power BI please?  

Regards,

Lee

Greg_Deckler
Super User
Super User

Hmm, any chance you could share some data, would be interesting to play around with this.


@ me in replies or I'll lose your thread!!!
Instead of a Kudo, please vote for this idea
Become an expert!: Enterprise DNA
External Tools: MSHGQM
YouTube Channel!: Microsoft Hates Greg
Latest book!:
Mastering Power BI 2nd Edition

DAX is easy, CALCULATE makes DAX hard...

Hi Greg.  Thanks for your reply.  Unfortunately I'm unable to share that data although it's just based on a simple table of month names, e.g. Jan-07, Feb-07, etc and a figure for each month.  Are you able to replicate something similar to see if you get the same strange forecast, i.e, is the forecast the same pattern for each projected year?  

Regards,

Lee

Seems like a lot of typing...


@ me in replies or I'll lose your thread!!!
Instead of a Kudo, please vote for this idea
Become an expert!: Enterprise DNA
External Tools: MSHGQM
YouTube Channel!: Microsoft Hates Greg
Latest book!:
Mastering Power BI 2nd Edition

DAX is easy, CALCULATE makes DAX hard...

Helpful resources

Announcements
Fabric Community Conference

Microsoft Fabric Community Conference

Join us at our first-ever Microsoft Fabric Community Conference, March 26-28, 2024 in Las Vegas with 100+ sessions by community experts and Microsoft engineering.

February 2024 Update Carousel

Power BI Monthly Update - February 2024

Check out the February 2024 Power BI update to learn about new features.

Fabric Career Hub

Microsoft Fabric Career Hub

Explore career paths and learn resources in Fabric.

Fabric Partner Community

Microsoft Fabric Partner Community

Engage with the Fabric engineering team, hear of product updates, business opportunities, and resources in the Fabric Partner Community.

Top Solution Authors