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PAW 57 Forecasting Time Dimension Detection

  • 1.  PAW 57 Forecasting Time Dimension Detection

    Posted Thu October 08, 2020 09:46 PM
    What's the trick to get PAW 57 forecaster to recognize a time like dimension? Things I have tried
    1) Alias's on/off
    2) Cubes with 2 time like dim
    3) Cubes with 1 time like dim
    4) Typing into the selection boxes

    Nothing seems to work. Is it expecting a dimension actually named "Time"?

    Thanks!

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    Ryan Clapp
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    #PlanningAnalyticswithWatson


  • 2.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Fri October 09, 2020 04:41 AM
    Hello Ryan,

    Your "time(s)" dimension simply need to be placed in column when running the forecast  or preview.

    Regards,

    https://www.ibm.com/support/knowledgecenter/SSD29G_2.0.0/com.ibm.swg.ba.cognos.tm1_prism_gs.2.0.0.doc/papr_forecast_features.html

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    Florence Mougnaud
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  • 3.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Fri October 09, 2020 04:43 AM
    They were, still not working.





  • 4.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Fri October 09, 2020 09:27 AM
    Edited by System Fri January 20, 2023 04:15 PM
    Hi Ryan,

    The time dimension can have any name and can be made of more than one dimension.

    The time series (that is made from one or more dimensions) need be continuous; and there can be issues when other reporting labels or multiple parent are in the time series too.  

    Sometimes creating a hierarchy with just the members to be considered in times series works.

    Martin

    ------------------------------
    STUART (MARTIN) PHILLIPS
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  • 5.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Fri October 09, 2020 01:01 PM
    Add a hierarchy and break the model because of ambiguous references.... Sounds like a great idea lol.





  • 6.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Fri October 09, 2020 02:04 PM
    I'm having similar issues, tried using a hierarchy with all my time periods on the columns of my cube view and get this...

    Failed to retreive forecast results for these time-series:
    Mens George Shoe Brown
    Mens Otis Boot Brown
    Mens James Sandal Brown
    No element specified for at least one of the dimensions in the cube!

    ------------------------------
    Mark White
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  • 7.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Fri October 09, 2020 04:52 PM
    Mark and Ryan,

    I messaged you individually and provided my direct email address.
    I want to understand your issues in more detail so we can help solve them.
    I hope to hear from you.

    Martin

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    STUART (MARTIN) PHILLIPS
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  • 8.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 07:12 AM
    Stuart, can you point me (and the rest of the community) at the documentation which sets out the prerequisites for forecasting to work? I have tried it against a real world dataset and find that I get either 'Invalid DataSet: Prediction Failed' or a success message but no content.

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    David Usherwood
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  • 9.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 07:17 AM
    I now have this working, but only with a 3 dimensional cube as per the Tutorial, my dimensions are Product, Time and Version, if I add any additional dimensions e.g. Sales Measures (so I can select the measure I want to forecast e.g. Qty or Revenue) then it fails with the message

    No element specified for at least one of the dimensions in the cube!

    I have tried dragging the measure onto the rows (so it's not a filter in the header of the cube view) but still have the same problem, is it that Forecasting can only work on a 3 dimensional cube as I was hoping to forecast across multiple dimensions at the same time e.g. Product by Customer or Product by Region etc.

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    Mark White
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  • 10.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 09:03 AM
    @Mark White I have been able to get a forecast to generate on a 5 dimensional cube. The key issue appears to be (as Stuart says) that the hierarchy(ies) on the column dimensions cannot have any rollups. ​FYI, the forecast which came out was the same amount each month whereas the history was different - so unusable.
    We really need solid documentation for this feature to move forward.

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    David Usherwood
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  • 11.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 10:50 AM
    I agree with David. Having more comprehensive documentation on this is a requirement for it to be really used.

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    Andrew Leighton
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  • 12.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Wed October 14, 2020 09:26 AM
    HI David,

    Here is a bit of an explanation on the straight line forecast you are getting (check "Period detection enhancements"), the doc is for Cognos Analytics, but it does apply to Planning at they used the same forecasting engine. I do agree that this bit should be added (and expanded) to the docs, inputting the seasonality manually might help. 

    https://www.ibm.com/support/knowledgecenter/SSEP7J_11.1.0/com.ibm.swg.ba.cognos.ca_new.doc/c_ca_nf_11_1_5_explorations.html

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    Julian
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  • 13.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 01:30 PM
    David,

    Correct, the forecasting feature is not limited by the number of dimensions in the cube.   However, I don't expect the same prediction/value for each month.
    I'll send you a message with my email, I would like to learn more about your case, so we can solve or document further.
    Thanks.

    Martin

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    STUART (MARTIN) PHILLIPS
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  • 14.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Tue October 13, 2020 01:41 PM
    David, I've seen the forecasting engine returning​ a straight line in cases when the data is not seasonal (or the algorithm cannot auto detect the seasonality) or when the data has too many outliers. If you can post an chart I could see if this is the case.

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    Julian
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  • 15.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 12:08 PM
    I don't know what I've done different, but now have a 4 dimension cube working, but getting strange forecasts.

    I have a product with historic sales between 0 (not sold in that season) and 3300 units yet two of the three forecasts are all forecasting negative sales, it appears to me that it's not auto detecting seasonality, so sees the decline in a winter product heading towards period 4 and expects it to continue into a negative number ???


    as other have said, we need more comprehensive documentation on this.


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    Mark White
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  • 16.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 12:14 PM
    Note that the documentation needs to cover both how to make it work and sufficient explanation of the underlying algorithms to allow the results to be defended to a client. I will admit I am something of a Luddite which it comes to AI - the term 'automated palmistry' comes to mind.

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    David Usherwood
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  • 17.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 12:44 PM
    Another interesting issue, although not my 2 time dimension issue, is the interaction with the config parameter ProportionSpreadToZeroCells. If you don't specify leaf level targets, your source contains consolidations, and this parameter is enabled you'll get a less than clear error message.

    For use in the real world you'll likely want a purpose built cube to interact with the forecaster.

    I think I already know the answer, but can an administrator control what cubes can be run through the forecaster?


    Sent from my mobile device





  • 18.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Tue October 13, 2020 01:55 PM
      |   view attached
    HI Ryan, there is a limitation on the forecasting when a member has multiple parents, from the docs:

    When the members of the dimensions, used to indicate the time (columns), have multiple parents, then the forecasting fails. With multiple parents, the correct order of those members is not known. To solve this limitation, create an alternative hierarchy for the dimensions that exclude the extra parents.


    I am not sure if this is the root cause of the issue you are experiencing,   there is no limit on the number of dimension on columns or rows as far as all the members on the slice are numerical. The chart with the envelop will not render if  nested dimensions are used on the column, but the forecasting should work. 

    Attaching a video with the workaround.

    ------------------------------
    Julian
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  • 19.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Wed October 14, 2020 04:28 PM
      |   view attached

    Hi Ryan, David:


    Forecasting should work with hierarchical (time) dimensions on the column, when there are multiple levels on the column, the preview button will not generate a chart (stat details should be presented), but the forecast will save the values. I wonder if the issue is as stated on the docs:

    When the members of the dimensions, used to indicate the time (columns), have multiple parents, then the forecasting fails. With multiple parents, the correct order of those members is not known. To solve this limitation, create an alternative hierarchy for the dimensions that exclude the extra parents.

    Attaching a video with that workaround 

    Julian



    ------------------------------
    Julian Solano Acosta
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  • 20.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Tue October 13, 2020 01:33 PM
    HI Mark, Is the screenshot showing all the historical data? As you said it seems the algorithm might  not be able to detect the seasonality given the data, to make sure that is the case, you run a preview on the specific time series and check the seasonality value on the stats details tab. Try to input the seasonality manually (advance tab), and check if any notes come back on the on the Result summary. 

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    Julian
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  • 21.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Tue October 13, 2020 01:42 PM
    Thanks Julian, there are 16 months of history, but it only seems to acknowledge the descent in values in the last few periods. I'll have a look at the seasonality on the advanced tab, however I wouldn't expect to have to do this on every item, my products consist of a mix of Winter, Summer and All Year products, so was hoping the forecasting algorithms could spot this in the data and forecast each product automatically, maybe I'm trying to do something that the product doesn't support just yet ?

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    Mark White
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  • 22.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Wed October 14, 2020 07:57 AM
    Hi Mark, is all the historical data displayed on the screenshot above? given the trend on the screenshot, in principle, the forecast looks accurate (forecasting do not apply any constraints i.e "sales cannot be negative"). The high and low lines are to indicate the confidence interval.

    Julian

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    Julian Solano Acosta
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  • 23.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Wed October 14, 2020 08:34 AM
      |   view attached
    Hi Julian

    yes, the data is all on screen, I've also attached a spreadsheet with the data so you can play with it yourself.

    The product is a Winter season only product, the Prior Year data PY shows sales in the Winter months, but no sales in the Summer then sales increasing again towards the next Winter, then decreasing again towards the Spring, we then want to forecast the remainder of the current year and sales for next year too.

    The forecasting algorithms don't seem to be recognising the pattern of historic data, just the decreasing sales in the Spring of the current year and assuming the sales will continue that trend below zero into negative sales.

    We need to understand if this is a limitation of the forecasting functionality and if so then not use it, or use it with caution, think it is especially important to have an option to be able to stop forecast values going negative, especially of being used for sales forecasting.

    Regards

    Mark



    ------------------------------
    Mark White
    ------------------------------

    Attachment(s)

    xlsx
    Winter Season Product.xlsx   21 KB 1 version


  • 24.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Wed October 14, 2020 10:57 AM
    Edited by System Fri January 20, 2023 04:38 PM
    HI Mark, thanks for the sample data, the algorithm by default tries to detect seasonality automatically, if it cannot be detected, then it picks  a non seasonal model, that is why a manual entry of seasonality might help, however if the seasonality entered is not matching the data, the engine does not apply such value, and a note is send back to the user (I ran your example with manual seasonality of 12,  see: note_seasonality.png). From the chart I do see that there is no repetition of the pattern (there is only 1 cycle), that explains why the seasonality is undetected and the manual one is not taken because nothing repeats after 12 periods, To test, I added another cycle (a copy of the first one), and ran it with seasonality "auto", now the forecast looks closer to what you are expecting (see predict_seasonality_auto_repeat.png), so in this case a bit more of historical data will clear your issue.

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    Julian
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  • 25.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Wed October 14, 2020 11:05 AM
    Thanks Julian, helps to understand how this works and where the limitations are, looks like my traditional Spread Profiles cube approach is needed for newer products that don't have more than 1 year of history.

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    Mark White
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  • 26.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 09:57 AM
    Hi Ryan,

    I experienced the same problem before. However, I noticed that the forecast and preview buttons will only be enabled if you select one of your row member.
    Maybe you can try selecting one of your row member and click forecast. 
    Refer to https://www.ibm.com/support/knowledgecenter/SSD29G_2.0.0/com.ibm.swg.ba.cognos.tm1_prism_gs.2.0.0.doc/prpa_forecast_tut_preview.html

    Hope above works for you as well.


    ------------------------------
    Tony Wijaya
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    ------------------------------
    Tony Wijaya
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  • 27.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 09:57 AM
    Hi Ryan,

    I experienced the same issue before. Apparently, the forecast feature will only be enabled if you select one of the row member.
    For my case, after selecting one of the row member, the preview and forecast buttons are enabled.

    You may refer to step 3 in this link https://www.ibm.com/support/knowledgecenter/SSD29G_2.0.0/com.ibm.swg.ba.cognos.tm1_prism_gs.2.0.0.doc/prpa_forecast_tut_preview.html


    Hope above works for you as well.

    ------------------------------
    Tony Wijaya
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  • 28.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Mon October 12, 2020 04:31 PM
    Hi

    Not sure there is much value in this facility for us, but one suggestion is that if it requires the columns to have base level periods with no consolidations, then using the leaf hierarchy on the time dimension would seem to give you this

    Regards

    Paul Simon

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    Paul Simon
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  • 29.  RE: PAW 57 Forecasting Time Dimension Detection

    Posted Tue October 13, 2020 11:32 AM
    Tony, Ryan

    The preview button is enabled if  1 row is selected, the forecast button is enabled if you select 1 or more rows on the cross tab, so forecasting is not limited to 1 row. 

    Julian

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    Julian Solano Acosta
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