Forecast in DAX

[KoenD]

Hi,

I am trying to make a prediction using data from the past few weeks. The formula boils down to the following:
prediction = [work stock per day] - ([past 7 days average time required] * [planned capacity])

Vooraad_prognose_v2 = (CALCULATE (
                SUM ( 'Data t b v  dashboard (2)'[Werkvoorraad per dag in stuks] ),
                LASTDATE('Data t b v  dashboard (2)'[Datum])
            )
        
            - (
                CALCULATE (
                    AVERAGE ( 'Data t b v  dashboard (2)'[Stuktijd in uur] ),
                    DATESBETWEEN ( 'Data t b v  dashboard (2)'[Datum], TODAY () - 7, TODAY () )
                )
                    * CALCULATE (
                        SUM ( 'Data t b v  dashboard (2)'[Geplande capaciteit beoordelen in uren] ),
                        LASTDATE('Data t b v  dashboard (2)'[Datum])
                    )))

Prediction looks great on historical data (dark blue line) :

However I want, ofcourse, to predict the following days. So it has to predict tomorrow, and according to that value the day after tommorrow, etc, etc. So ultimately I can see when the work stock reaches 0. What do I have to do, to make this actually predictive?

I am aware of the build-in prediction function, but the end goal is to dynamically edit some of the input values with different parameters.

Thanks in advance!

[Greg_Deckler]

@KoenD This might help: Days of Supply - Microsoft Power BI Community

Otherwise:

Sorry, having trouble following, can you post sample data as text and expected output?
Not really enough information to go on, please first check if your issue is a common issue listed here: https://community.powerbi.com/t5/Community-Blog/Before-You-Post-Read-This/ba-p/1116882

Also, please see this post regarding How to Get Your Question Answered Quickly: https://community.powerbi.com/t5/Community-Blog/How-to-Get-Your-Question-Answered-Quickly/ba-p/38490

The most important parts are:
1. Sample data as text, use the table tool in the editing bar
2. Expected output from sample data
3. Explanation in words of how to get from 1. to 2.