Time Series Forecasting for many examples

NoelNoel Member Posts: 2 Learner I
Hi All-
[Apologies in advance for any confusing or vague language I may use; I'm not a data scientist, so I don't know the proper terminology.]

Say I have a data set of sales volume over time for a retailer that sells screwdrivers. Their product catalog really runs the gamut: flathead, phillips, torx, long, short, every color you can think of, and on and on. If you wanted to forecast demand, you could create a model for one series at a time for each product (e.g. short, yellow, flathead screwdrivers and then medium length, purple, torx drivers with fat handles, etc), or one could aggregate sales for all phillips head screwdrivers or all the different types of screwdrivers in order to collapse them into one series.
For some reason, though, let's say you wanted to use all the data from every type of screwdrivers individually to train a model. For each date, you would have data points for every type of screwdriver in inventory. 

What is the "right way" to represent this in RapidMiner?

@sgenzer ;@tftemme

Answers

  • Telcontar120Telcontar120 Moderator, RapidMiner Certified Analyst, RapidMiner Certified Expert, Member Posts: 975   Unicorn
    I may not be understanding your question.  When you say "you wanted to use all the data from every type of screwdriver individually to train a model," do you mean that you want a single model representing total demand for screwdrivers?  If so, then the conventional approach would be to first aggregate all sales by date, and then use the traditional time series approaches to model that (e.g, it could be ARIMA or Holt-Winters, etc.).
    Brian T.
    Lindon Ventures 
    Data Science Consulting from Certified RapidMiner Experts
    Noel
  • NoelNoel Member Posts: 2 Learner I
    Thanks for the response, Telcontar120!
    Assume I have daily sales numbers for every flavor of screwdriver carried by the retailer and do not want to aggregate the data into a single time series. (Unfortunately, my ability to use this analogy breaks down here because I can't think of why one would want to model sales of each type of screwdriver individually instead of aggregating them... I can try to come up with another analogy if it is helpful, but I'm afraid it will muddy the water.)
  • Telcontar120Telcontar120 Moderator, RapidMiner Certified Analyst, RapidMiner Certified Expert, Member Posts: 975   Unicorn
    If you don't want to aggregate any sales data, then aren't you back to forecasting sales for each individual item (or at whatever level of granularity your data currently exists)?  But I thought that is what you said you did not want to do in the OP.  However, RapidMiner certainly will support it, you will just need to iterate through and provide a different target forecast attribute each time.
    If that isn't correct, you'll probably need to post a sample data file to be more clear on what exactly it is you are trying to accomplish.

    Brian T.
    Lindon Ventures 
    Data Science Consulting from Certified RapidMiner Experts
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