Forecast Amount

Hi there,

I would like to create some measures to calculate the forecast amount but I am unable to get the correct amount.

Sample data here. Current month data and blank date data will be considered as forecast data.

1. I have a monthly rate table and I want to calculate the forecast count for current month based on last month count by multiplying the monthly rate. E.g. There is 166 count in Jan'21 and Feb rate is -2%. To get Feb'21 count, I have to multiply the -2% with last month count. How to incorporate the rate by using previous month data?
2. I have fixed rate of 86% for FS order type forecast count. After I got the total forecast count for current month, I have to multiply it with 86% for only FS order type ID.
3. Then the forecast count for Other order type will be the total forecast count for current month minus the count for FS order type.
4. There is an estimate for each ID and I need to calculate the proportion amount for FS order type and other order type. I need to take the count of point #2 divide by total ID count for "current month and blank date" data then multiply by the estimates. Same goes to the Other order type.
5. Sum the amount in Point #4 for FS and Other order type.

Below is explanation of above points.