Having trouble with data model relationships

Riny_van_Eekelen Thank you for taking your time to answer my questions. OK, I'm on my computer now, let me try and clarify:

To answer the first question: there is only one manufacturer per part number, thankfully.

The first table, SIOP (24 month rolling customer demand forecast) looks like this:

It's basically a finance generated report of part numbers, descriptions, and monthly demand volumes, on a rolling 24 month forecast. This report has all of the detailed information - demand by plant, by project, by customer program. The part number (main identifier) can appear many times.

The second table, EDI (24 month plant order demand) looks like this:

This report is much simpler - it only includes part numbers and plants - it does NOT delineate by project, does not include manufacturer name, etc. I will note - plant codes are the SAME between the two files.

The end goal of this is to build a dashboard that will let me easily compare the two data sources, and report volume by part number, sliced by plant, manufacturer, and tech density.

It's very easy to add manufacturer to the memory master key file - and all the things I'm trying to do I can do very easily if I'm looking at ONE data source - either SIOP or EDI. The minute I try to slice or filter EDI by manufacturer (doesn't exist in SIOP), or even try and slice by SIOP by EDI plant code - it fails.

This doesn't make any sense to me - because it defeats the point of multiple tables so far, to me. If I need to create a master that contains everything, I guess I'm missing the point of the data model, or perhaps I'm just doing it wrong 🙂 Thanks for your help.