My goal is to have the equation below:
MTBF (Mean Time Between Failure)=(total # of equip in each category * 12) / (rolling 12 month sum of breakdowns in category)
My first data set contains every piece of equipment and references its equipment type.
My second data set contains the notification date, breakdown indicator and equipment for all equipment that had issues. I'm only drawing data for the ones that actually have the breakdown indicator:
I also have a Calendar reference table.
I will need to be able to graph total MTBF over all equipment types, and also break it down by equipment type monthly.
You could create the relationship between first data and second data by equipment column.
and create the relationship between Calendar reference table and second data by notification date column.
Then create a measure like this: