Hi,
I’m somewhat new to epicor, so please excuse my lack of knowledge.
I’m trying to create a way to view forecast changes over time.
Example a part today might have a forecast of 100, but next month it might be 500. I would like to be able to compare the changes of the forecast information for a specific part based on the date.
My plan is to get this data into power bi for slicing, but what are the appropriate tables in epicor to get this information, and do the tables keep track of the changes as a transaction? Or do I need to take my query and use a stored procedure to store in another table that will keep a record of what the part forecast as at a particular time?
Welcome aboard Tyler. Passenger88 nice handle… 
Going to direct you to this post first.
Tips for asking question on the forum - Experts’ Corner - Epicor User Help Forum
The Parttran is the table you will want to look at, and the using the field help against the fields in the part tracker may also yield some information to help you with forecasts.
You will want to take a look at the guides of developing BAQs.
There are a few posts on working with Power BI here as well.
Hope the information helps.